Biomolecules and Enzymes 1. Macromolecules

a. Large complex molecules (polymer) made up of repeating subunits (monomers)

b. Carbohydrates (polysaccharide)

i. Elements: carbon, hydrogen, and oxygen (1:2:1 ratio, therefore #C = #O)

ii. Subunit/monomer: monosaccharide (sugar)

iii. Examples: fruits/veggies, bread/pasta, cellulose in plants, glucose

iv. Used for immediate (short-term) energy

c. Lipids

i. Elements: carbon, hydrogen, and oxygen (#C ≥ #O)

ii. Subunit/monomer: fatty acid chains and glycerol

iii. Examples: fats (butter), oils, and waxes

iv. Uses – long term energy storage (keeps your warm) & phospholipid bilayer

d. Proteins (polypeptide)

i. Elements: carbon, hydrogen, oxygen , nitrogen (and sometimes sulfur)

ii. Subunit/monomer: amino acids connected with peptide bonds

iii. Examples: meat, eggs, fish, nuts, beans, enzymes

iv. Uses – enzymes (speed up chemical reactions), regulation of reactions, & transport of molecules

e. Nucleic Acids

i. Elements: carbon, hydrogen, oxygen, nitrogen, and phosphorous

ii. Subunit/monomer: nucleotides

iii. Examples: DNA and RNA

iv. Uses – store and transmit genetic information

f. Pictures of the 4 biomolecules

g. Formation of polymers – Dehydration Synthesis (water removed to bind 2 monomers together)

h. Breakdown of polymers – Hydrolysis (water added to break the bonds of a polymer to divide into its

monomers)

2. Enzymes (catalysts)

a. Proteins that speed up chemical reactions

b. Remain unchanged by the reaction, do not get used up

c. Work by lowering activation energy (minimum energy needed

for a chemical reaction to occur)

d. They have a specific shape, which determines which substrate

they work with (lock-and-key) Specificity = only one substrate

can bind with one enzyme in the active site

e. Substrates bind to the enzymes active site; the enzyme “hugs”

the substrate – induced fit

Cell Structures and Functions

1. Cell Theory

a. All living things are composed of cells

b. Cells are the basic unit of structure and function in living things (cell = smallest unit capable of

performing life functions)

c. All cells come from preexisting cells through mitosis

2. Levels of Organization (small to large): atom molecule/compound organelle cell tissue organ

organ system organism population community ecosystem

3. Prokaryote vs. Eukaryote Cells

a. Similarities (DR.CC)

i. DNA – instructions for life

ii. Ribosomes – make protein

iii. Cytoplasm – protects

iv. Cell membrane – controls in/out (homeostasis)

b. Differences

Prokaryotic Eukaryotic

*Simple *Complex

*Unicellular *Unicellular OR multicellular

*NO membrane-bound organelles

*DO have membrane-bound organelles

*Reproduction via binary fission

*Reproduction via mitosis & meiosis

*Bacteria *Protists, fungi, plants, and animals

4. Organelle Structures and Functions (organelles are small structures that perform various functions for the cell)

a. Cell Wall

i. Found in bacteria, fungi, and plants (outside the cell membrane)

ii. Supports and protects cells

b. Cell Membrane

i. Double layer of lipids and protein that surrounds ALL cells

ii. Controls movement into and out of the cell (semi-permeable); therefore, controls homeostasis

c. Cytoplasm: Gel-like mix (80% water) that protects the organelles

d. Nucleus - Controls cell activities and contains the genetic material (DNA)

e. Mitochondria – Produces ATP (energy) by cell respiration

f. Rough ER – covered with ribosomes; transports proteins to Golgi

g. Smooth ER – Makes steroids/ions and transports the to the Golgi; detoxifies poisons and drugs

h. Ribosomes – make protein

i. Golgi – modifies, sorts, and packages molecules from the ER and distributes them with vesicles

j. Lysosome – has digestive enzymes that break down wastes and old cell parts

k. Vacuole – stores water, food, and wastes; maintains the shape of plant cells (turgor pressure)

l. Chloroplasts – make food (glucose) out of sun energy for plants

Cell Transport

5. Cell Transport

a. Homeostasis: maintaining a stable body system. Maintained by the cell membrane

b. Cell membrane is selectively (semi)permeable – lets some things in/out but not others

c. Concentration gradient – A high concentration of molecules in one area, spreading out to a low

concentration of molecules in another area

d. Passive Transport – the movement of molecules DOWN/WITH their concentration gradient without

using energy (from high to low concentration)

i. Diffusion: movement of small molecules from high to low concentration

ii. Facilitated Diffusion: movement of small molecules from high to low with the help of proteins

iii. Osmosis: movement of water molecules from high to low concentration

e. Active transport – movement of molecules UP/AGAINST their concentration gradient, which requires

energy (from low to high concentration) – requires ATP

i. Transport proteins – carry molecules across the membrane

ii. Endocytosis and exocytosis (entering and leaving the cell in vesicles)

f. Osmotic solutions

i. Isotonic

1. Solution has same amount of “stuff” and water

2. No net movement of water

3. Cell stays the same (true for plant AND animal cells)

ii. Hypertonic

1. Solution has lots of “stuff” and not much water

2. Net movement of water OUT of the cell

3. Cell shrivels (true for plant AND animal cells)

iii. Hypotonic

1. Solution has lots of water and not much “stuff”

2. Net movement of water INTO the cells

3. Animal cells swell and burst (no cell wall to support)

4. Plant cells display good turgor pressure

Photosynthesis and Cellular Respiration 1. How Do Cells Obtain Energy?

a. Types of organisms

i. Heterotrophs – must eat food to get energy

ii. Autotrophs – make their own food

b. ALL energy in living organisms comes from the sun (food pyramid)

2. Cellular Respiration (turns food into ATP energy)

a. Occurs in ALL eukaryotic organisms (protists, fungi, plants, animals) since they all need energy to survive

b. Organelle: mitochondria

c. BREAKS glucose down to release chemical energy (ATP)

d. C6H12O6 + 6O2 6H2O + 6CO2 + 36/38 ATP (energy) e. Aerobic respiration (aerobic = needs oxygen) occurs in the mitochondria – makes 34/36 ATP

f. Anaerobic respiration (no oxygen present) occurs in the cytoplasm – makes 2 ATP

i. Alcoholic Fermentation - occurs in plants and fungi (yeast)

ii. Lactic Acid Fermentation - occurs in animals (causes pain in muscles after a workout)

g. Energy source = glucose (chemical food energy); Energy product = ATP (chemical energy)

3. Photosynthesis (turns sunlight into food)

a. Occurs in plants and some protists (everyone else has to eat their food)

b. Organelle: chloroplast

c. Sunlight = radiant energy

d. Uses radiant energy to MAKE glucose

e. 6CO2 + 6H2O + sunlight C6H12O6 + 6O2 f. Beginning of all food chains – so ALL life is supported by photosynthesis

g. Energy source = sunlight (radiant energy); Energy product = glucose (chemical food energy)

h. Structure of leaves

i. Stomata – pores on the underside of leaves that let gases move in and out. Open during the day

and usually closed at night

ii. Xylem – moves water up to the leaves from the roots

iii. Phloem – moves glucose down to the rest of the plant from the leaves

i. What affects photosynthesis

i. Light intensity – the more light, the faster the rate of photosynthesis (to a point)

ii. Carbon dioxide – the more CO2, the faster the rate of photosynthesis (to a point)

iii. Temperature – if it is too high or too low, the rate drops

*The products of respiration are the reactants

of photosynthesis

*The reactants of photosynthesis are the

products of respiration

Cell Cycle 1. Cell Cycle and Mitosis

a. Cells divide so we can grow, repair damaged cells, and replace old cells (GRR – growth, repair, & replace)

b. Chromosomes

i. Humans have 46 total chromosomes - 23 chromosomes from each parent

ii. When DNA is loose it is called chromatin (like this during interphase and resting), when it is

coiled, it is called a chromosome (like this during mitosis); chromosomes have an “X” shape

c. Cell division in prokaryotes (bacteria) is called binary fission

d. Cell Cycle in eukaryotes

i. Interphase

1. G1 – first growth phase

2. **S – synthesis (DNA replicates)**

3. G2 – second growth phase

ii. Mitosis – 4 stages (PMAT)

1. Prophase

a. DNA condenses into chromosomes

b. Nuclear membrane breaks down

c. Spindle fibers form

2. Metaphase

a. Spindle fibers attach to the chromosomes

b. Chromosomes move to the equatorial plate (middle of cell)

3. Anaphase

a. Spindle fibers pulls sister chromatids to opposite ends of the cell

4. Telophase

a. Chromosomes de-condense

b. Two new nuclear membranes form

c. Spindle fibers break down

iii. Cytokinesis

1. Division of the cytoplasm; occurs after mitosis is complete

2. Daughter cells of mitosis: two genetically identical cells – same number of chromosomes

as each other and as the parent cell

e. Problems with mitosis

i. If cells do not rest, and stay in the cell cycle dividing uncontrolled, cancer occurs

ii. Cell become cancer if they skip checkpoints

iii. Cancer cells do NOT go into G0 (resting phase)

DNA Structure and Replication 1. DNA Structure and Replication

a. History of DNA – 1950s

i. Rosalind Franklin used X rays to photograph DNA

ii. James Watson and Francis Crick used photograph to determine DNA is a double helix

b. Structure of DNA

i. DNA is made of the biomolecule nucleic acids, which are made up of the monomer nucleotides

ii. Nucleotides – made of a phosphate group, sugar (deoxyribose), and one of 4 nitrogenous bases

iii. Backbone is made of sugar and phosphate groups, connected by phosphate bonds. The function

is to provide double-helix structure and support

iv. The middle is made of the nitrogen bases (adenine, thymine, guanine, and cytosine) connected

by hydrogen bonds

1. A always pairs with T (2 hydrogen bonds)

2. G always pairs with C (3 hydrogen bonds)

v. *The sequence of the nitrogen bases is what determines your traits and characteristics (you

use the sequence to build proteins)

c. Why is DNA Important?

i. Gene = specific sequence of bases

ii. 20-30 thousand genes per chromosome (46 chromosomes, or 23 pairs, per person)

iii. ALL body cells contain a complete copy of your ENTIRE genome (all your genes) – cells do

different things because they turn on different genes depending on their job

iv. ***ALL living organisms contain DNA, and the DNA for all is made out of the same things. Only

difference is the sequences of bases***

2. DNA Replication

a. Occurs during the S stage of interphase during the cell cycle

b. The enzyme helicase breaking the hydrogen bonds holding the nitrogen base pairs together

c. The two sides of the DNA separate to be used as template strands

d. The enzyme DNA polymerase adds new nitrogen bases to the template strands

e. End result is two identical pieces of DNA, each with one old strand and one new strand

f. This kind of replication is known as semi-conservative (one old strand + one new strand)

PROTEIN SYNTHESIS

3. DNA vs. RNA

a. DNA is double stranded; RNA is single-stranded

b. DNA has thymine; RNA has uracil

4. Messenger RNA (mRNA) – copies DNA code & carries the info from nucleus to ribosomes

5. Genetic Code

a. Ribosomes read the mRNA nucleotides in groups of 3 bases (3 bases = codon)

6. Steps of protein synthesis

a. Step One – Transcription

i. Occurs in the nucleus

ii. DNA strand (template strand) mRNA

1. T A A U

2. G C C G

iii. mRNA leaves the nucleus through the nuclear pores and goes to the ribosome (floating in

cytoplasm or attached to rough ER)

b. Step Two – Translation

i. Occurs at a ribosome

ii. The process of decoding mRNA and turning it into a polypeptide chain (protein)

iii. End Product: A protein in its primary structure (string of amino acids bonded by peptide bonds)

7. Gene Expression

a. Every body cell has a full set of DNA (46 chromosomes), but different cells do different things

b. Each cell only turns on the genes it needs to do its job

c. Gene expression can be influenced by: the environment, hormones, and chemicals

MUTATIONS

1. Mutation means change

2. Types

a. Substitution – one nucleotide is replaced with another

i. This is a type of point mutation (only affecting a single nucleotide)

ii. Total number of bases stays the same

iii. Types

1. Silent – Same amino acid

2. Missense –Different amino acid

3. Nonsense –STOP codon (no amino acid)

iv. Frameshift mutations

1. Causes changes in ALL codons that come after the mutation

2. Total number of bases either increases or decreases

3. Types

a. Deletion – a nucleotide is taken out completely

b. Insertion – an extra nucleotide is added to the sequence

POINT MUTATIONS FRAMESHIFT MUTATIONS

MEIOSIS

1. Basis for sexual reproduction

2. Similar to mitosis, but division happens twice

3. Starts with one cell that has 46 single-stranded chromosomes

4. Results in 4 cells that each have half the amount of genetic information – 23 chromosomes

5. For humans, these are egg and sperm cells (gametes)

6. Starts with Interphase (just like mitosis), during which the cell grows and DNA doubles.

7. Occurs in 2 phases – Meiosis I and Meiosis II (this is known as reduction-division)

8. Meiosis I

a. Prophase I – chromatin condenses into chromosomes and homologs pair up (called tetrads) and nuclear

membrane breaks down. Crossing over occurs (pieces of chromosomes or genes are exchanged between

the tetrads) to increase genetic variation in offspring

b. Metaphase I – Spindle fibers attach to the double banded chromosomes and push them to the middle of

the cell (equatorial plate)

c. Anaphase I – homologous chromosomes separate and move to opposite pole

d. Telophase I – two nuclear envelopes reassemble and cytokinesis divides the cell in two

9. Meiosis II

a. Prophase II – the nuclear membranes break down and spindle fibers form

b. Metaphase II chromosomes to the equator of the cell

c. Anaphase II – Sister chromatids are ripped apart and moved to opposite poles

d. Telophase II – four new nuclear envelopes form, the and cytokinesis divides both cells in two (ends with

4 cells)

GENETICS

1. Meiosis – basis for sexual reproduction

a. Similar to mitosis, but division happens twice

b. Results in 4 cells that each have half the amount of genetic information (n = haploid) – 23 chromosomes

c. For humans, these are egg and sperm cells (gametes)

d. Starts with Interphase (just like mitosis), during which the cell grows and DNA doubles. For humans, that

means 46 chromosomes double to 92 chromosomes

e. Occurs in 2 phases – Meiosis I and Meiosis II (this is known as reduction-division)

f. Meiosis I

i. Prophase I – chromatin condenses into chromosomes and homologs pair up (called tetrads) and

nuclear membrane breaks down. Crossing over occurs (pieces of chromosomes or genes are

exchanged between the tetrads) to increase genetic variation in offspring

ii. Metaphase I – Spindle fibers attach to the double banded chromosomes and push them to the

middle of the cell (equatorial plate)

iii. Anaphase I – homologous chromosomes separate and move to opposite pole

iv. Telophase I – two nuclear envelopes reassemble and cytokinesis divides the cell in two

g. Meiosis II

i. Prophase II – the nuclear membranes break down and spindle fibers form

ii. Metaphase II chromosomes to the equator of the cell

iii. Anaphase II – Sister chromatids are ripped apart and moved to opposite poles

iv. Telophase II – four new nuclear envelopes assemble, chromosomes decondense, the and

cytokinesis divides both cells in two

2. Genetics

a. Terminology

i. Trait – any characteristic passed from parent to offspring

ii. Heredity – passing of traits from parents to offspring

iii. Genetics – the study of heredity

iv. Genes – control the expression of traits

v. Alleles – two forms of a gene (can be dominant or recessive)

vi. Dominant allele – the stronger of two alleles, covers up the recessive if present, and is

represented by a capital letter

vii. Recessive allele – the weaker of two alleles that only shows up if the organism has two copies,

represented by a lowercase letter

viii. Genotype – the genetic combinations for a trait (the letters)

ix. Phenotype – the physical feature resulting from the genotype (what the organism LOOKS like)

x. Homozygous –two of the same alleles (either two dominant or two recessive); also called pure

Meiosis

I

Meiosis

II

xi. Heterozygous – have two different alleles; one dominant and one recessive; also called a hybrid

xii. Punnett Squares – used to held geneticists determine probable outcomes for offspring

b. Crosses – Mendelian

1. Monohybrid cross – a cross involving a single trait

Example #1: Pea plant seed shape

Alleles: Dominant = round (R) Recessive = wrinkled (r)

Cross: Pure round seed X wrinkled seed

Genotype of offspring: 100% Rr

Phenotype of offspring: 100% round

Example #2: Pea plant seed shape

Alleles: Dominant = round (R) Recessive = wrinkled (r)

Cross: heterozygous X heterozygous

Genotype of offspring: 25% RR, 50% Rr, 25% rr

Genotypic ratio: 1:2:1

Phenotype of offspring: 75% round, 25% wrinkled

Phenotypic ratio: 3:1

2. Dihybrid cross – a cross involving two traits

Example: Fruit fly body color and eye color

Alleles: Dominant = Black body (B) Recessive = Brown body (b)

Black eyes (R) Red eyes (r)

Cross: two organisms that are hybrid for BOTH traits (BbRr X BbRr). What are the chances the

offspring will be BBRr?

Chances of BB = ¼ Chances of Rr = 2/4 = ½

Chances of BOTH BB AND Rr = ¼ * ½ = 1/8

EVOLUTION 1. Evidence of Evolution

a. Anatomical Homologies – structural features with a common evolutionary origin (ex: human arm & a bat wing)

i. Vestigial structures – a body structure in a present-day organism that was useful in an ancestor but is not

useful to the individual (ex: appendix)

b. Developmental Homologies (Embryology)

i. Embryos of fish, reptiles, birds, and mammals all have a tail, pharyngeal gills, and a notochord

ii. This suggests evolution from a distant, common ancestor

c. Molecular Homologies – the more similar two species are, the more DNA they will have in common (therefore,

they will also have more similar amino acid sequences)

d. Fossil Record – newest fossils are on top, older ones are buried deeper down

i. Stasis: when organisms remain the same over long periods of time

ii. Gradualism: organisms changing gradually over time

iii. Punctuated Equilibrium: a sudden change in organisms, creating new species

e. Biogeography – the study of how plants and animals are distributed on Earth

i. Similar environments lead to similar adaptations

ii. Pangea – similar fossils found on different continents give evidence of tectonic plate movement

iii. Geographical barriers (mountains and rivers) cause physical separation and indicate areas of different

species

2. Mechanisms of Evolution

a. Genetic Drift

i. Random change in allele frequency

ii. Caused by natural disasters

iii. Leads to a decrease in genetic diversity/variation

iv. Ex: a tornado or hurricane wipes out part of a population

b. Gene flow

i. Movement of alleles from one population to another

ii. Caused by migration (movement)

iii. Leads to increase genetic variation in the new population, & a decrease of variation in the old population

iv. Ex: A bird migrating from one flock to another

c. Natural Selection: Survival of the fittest –

i. Organisms that are best adapted to their environment will survive and reproduce

ii. Caused by the environment

iii. Can lead to a loss of genetic diversity/variation

iv. Examples

1. Stabilizing – favors the average value

2. Directional – favors the beneficial trait (one of the extremes)

3. Disruptive – favors both extremes; eventually leads to two different species

d. Mutations:

i. A change in nucleotide bases

ii. Caused by random chance or environmental factors

iii. Leads to an increase in genetic diversity/variation

iv. Ex: cancer, Down’s Syndrome, color blindness

3. Adaptations

a. Mimicry – one species resembles another species in order to trick predators into thinking it is a more dangerous

organism

b. Camouflage – allows species to blend in with their environment

c. Physiological adaptations – changes in an organism’s metabolic processes (faster metabolism)

d. Antibiotic resistance – some antibiotics are no longer effective against bacteria

CLASSIFICATION

1. Cladograms and Dichotomous Keys

a. Cladograms – A branching diagram that shows the evolutionary history of a species

b. The closer groups are on a cladogram, the more similarities they have, and the more recent their

common ancestor

c. Dichotomous – to divide in two

d. A series of two choices, leading to the classification of an organism

2. Scientific name = Genus species

3. Binomial nomenclature (2-part name)

4. Taxonomy: the study of classification. It is important because –

a. Scientific names are less confusing than common names

b. It shows the relationships between organisms and their ancestors

5. Today, scientists classify organisms based on

a. Physical similarities

b. Genetic similarities

c. Biochemical similarities

d. Behavioral similarities

6. Order of the 8 classification groups from most general to most specific

a. Domain (Dear) – there are 3

b. Kingdom (King) – there are 6

c. Phylum (Philip) – there are 54

d. Class (Cried)

e. Order (Out)

f. Family (For)

g. Genus (Good)

h. Species (Shoes) – there are approximately 8.7 million

7. Species – members of the same group the can interbreed and produce fertile offspring

8. 3 Domains and 6 Kingdoms – each has a set of characteristics that bind the organisms in that group together

a. Domain Bacteria – common bacteria

i. Kingdom Eubacteria

1. Unicellular and prokaryotic (no nucleus or other membrane-bound organelles)

2. Most can’t make their own food and must live in or on other organisms (heterotrophic)

3. Have cell walls and are decomposers

4. Asexual reproduction (binary fission)

b. Domain Archae – ancient bacteria

i. Kingdom Archebacteria

1. Unicellular and prokaryotic (no nucleus or other membrane-bound organelles)

2. Found in “extreme” environments (lots of gas, super hot, very salty, etc)

3. Most digest chemicals not usable by other organisms (heterotrophic)

4. Have cell walls and are decomposers

5. Asexual reproduction (binary fission)

c. Domain Eukarya – eukaryotic organisms

i. Kingdom Protista

1. Eukaryotic (DO have membrane -bound organelles)

2. Usually multi-celled (but some are unicellular)

3. Many make their own food, but some cannot (some autotrophic; some heterotrophic)

4. Sexual reproduction via mitosis and meiosis OR asexual reproduction via binary fission

5. Some have cells walls, but others do not

6. Some are decomposers, but others are not

7. “Odds-and-ends” kingdom filled with organisms that simply don’t fit anywhere else

ii. Kingdom Fungi

1. Eukaryotic (DO have membrane -bound organelles)

2. Multi-cellular (except for yeast)

3. Has cell walls made of chitin

4. Can perform both sexual and asexual reproduction

5. Heterotrophic and a decomposer – cannot make its own food, so it lives in or on living

or dead organisms

iii. Kingdom Plantae

1. Multicellular and eukaryotic

2. Has a large vacuole, chloroplasts, and cell walls

3. Autotrophs (make their own food using sunlight)

4. Sexual reproduction via mitosis and meiosis

5. NOT a decomposer

iv. Kingdom Animalia

1. Multicellular and eukaryotic

2. Cannot make their own food, so they eat plants, hunt (eat other animals), filter feed, or

scavenge food (heterotrophs)

3. Sexual reproduction via mitosis and meiosis

4. NO cell walls and NOT a decomposer

MICROBIOLOGY – VIRUSES AND BACTERIA

1. Bacteria

a. Structure

i. Prokaryotic (no membrane-bound organelles) and unicellular

ii. DO have DNA, ribosomes, cytoplasm, and cell membrane

1. DNA is a single, circular chromosomes

iii. Also have a cell wall

b. Growth

i. Many act as decomposers (recycling nutrients)

ii. Some cause disease – pathogens

iii. Some are useful – make food (yogurt/cheese), help us digest our food

c. Reproduction

i. Asexual – binary fission

1. Single chromosome replicates, then the cell divides

2. All new bacteria cells are identical

ii. Sexual – conjugation

1. A tube forms between two bacteria to exchange genetic information

2. New cells are not identical

d. Antibiotics

i. Used to treat bacterial infections

ii. Usually target bacterial cell walls (good for us since our cells do not have cell walls)

iii. Antibiotics can target bad AND good bacteria

iv. NOT effective against viruses

2. Viruses

a. Viruses are NOT alive!

b. Virus = non-cellular particle made of DNA or RNA surrounded by a protein coat (capsid)

c. Only capable of reproducing when inside a host cell (otherwise they are inactive)

d. Most viruses only infect specific host cells

e. Bacteriophage – a virus that infects bacteria

f. Retrovirus – contains RNA instead of DNA

g. Methods of infection

i. Lytic Cycle

1. Attachment to the cell

2. Penetration/injection of viral DNA or RNA

3. Replication (biosynthesis) of new viral proteins and nucleic acids using host cell

machinery

4. Assembly (maturation) of new viruses

5. Release of new viruses into the environment (lysis of the cell)

ii. Lysogenic Cycle – some viruses can lay dormant inside the cell for a time – up to years – before

activating in response to some external signal

1. Attachment to the cell

2. Penetration/injection of viral DNA or RNA

3. Phage DNA integrates into the host chromosome and lies dormant until triggered by an

outside signal

4. Replication (biosynthesis) of new viral proteins and nucleic acids using host cell

machinery

5. Assembly (maturation) of new viruses

6. Release of new viruses into the environment (lysis of the cell)

h. How viruses spread

i. Droplets of moisture (cold/flu)

ii. Contact with a contaminated object

iii. Bite from an infected animal (rabies)

iv. Bodily fluids – blood, sexual fluids (HIV)

v. Vectors like mosquitoes (zika, west nile)

i. Treatment

i. Antibiotic do NOT treat viruses

ii. If you get sick with a virus, usually the only thing to do is rest and drink plenty of fluids

iii. Vaccines – giving a person a weakened or heat-killed virus to stimulate their immune system

into making antibodies against the virus to protect against future attack

j. Types

i. Influenza

1. RNA Virus (retrovirus)

2. Lytic cycle (you get sick quickly)

3. Transmitted through contaminated objects & droplets of moisture (sneezing/coughing)

4. Need to get a vaccine every year because the virus mutates so quickly

ii. HIV

1. RNA virus (retrovirus)

2. Lysogenic cycle (it can take years before you know you’re sick)

3. Transmitted through blood and bodily fluids

4. Attacks immune systems cells, which leaves you unable to defend against other

pathogens

ANIMAL SYSTEMS 1. Skeletal

a. Supports the body and enables bending/twisting

b. Protects organs (brain, kidneys, heart and lungs)

c. Major organ: bones

2. Muscular

a. Responsible for movement

b. Major organ: muscle

c. Specialized cell: muscle

i. Cardiac: involuntary movement of the heart

ii. Skeletal: voluntary movement of the skeleton

iii. Smooth: involuntary movement inside the body (urination, digestion, childbirth)

3. Integumentary (skin)

a. First line of protection against germs

b. Prevents water loss

c. Maintains temperature (blood vessels can release or conserve heat)

d. Major organ: skin

e. Specialized cell: epithelium

4. Nervous

a. Controls all mental and bodily functions

b. Nerves receive stimuli from the world (5 senses), and the brain decides how to respond

c. Major organs: brain and spinal cords

d. Specialized cell: neuron

5. Endocrine

a. Releases hormones to keep the body at homeostasis (ex: insulin and adrenaline)

b. Major organ: glands

6. Reproductive

a. Produces male and female sex cells (gametes) and nourishes a developing baby

b. Major organs: sex organs

c. Specialized cells: egg and sperm

7. Digestive

a. Breaks down food so nutrients can be absorbed

b. Major organs: esophagus, stomach, intestines

8. Excretory

a. Eliminates wastes and excess water through sweating and urination

b. Major organs: kidney, bladder, and skin

9. Immune

a. Defends your body from germs and harmful, infection-causing organisms (pathogens)

b. Major organs: blood vessels

c. Specialized cell: blood (white blood cells are the disease-fighters)

10. Circulatory

a. Pumps blood, which carries oxygen & nutrients to body cells and takes CO2 and wastes away from the cells

b. Major organ: heart

c. Specialized cell: blood (red blood cells)

11. Respiratory

a. Responsible for gas exchange (oxygen in, carbon dioxide out)

b. Major organ: lungs

PLANT SYSTEMS

1. Transport

a. Root System

i. Take in water and minerals from ground

ii. Anchor the plant into the soil

b. Shoot System

i. Stems

1. Two-way transport – water up (through xylem), food down (through phloem)

2. Hold leaves up for sun exposure

ii. Leaves

1. Function: photosynthesis

a. CO2 + H2O + light C6H12O6 + O2

2. Stomata (openings on underside of the leaf) allow gases (CO2 and O2) to move in & out

3. Opening and closing of the stomata regulated by guard cells

4. Cuticle – waxy covering on the leaf that helps prevent water loss (transpiration)

c. Vascular tissue – used for transport

i. Xylem – carries water and nutrients UP the plant, from the roots to the leaves

ii. Phloem – carried food DOWN the plant to the stem and roots for use and storage

2. Reproduction

a. Pollination

i. To bring together egg and sperm to create offspring (babies)

ii. Male parts (stamen)

1. Anthers: produce pollen (plant sperm)

2. Filament: holds up the anther

iii. Female parts (pistil)

1. Stigma: the sticky tip that receives the pollen

2. Style: the tube that connects the stigma to the ovary

3. Ovary: where the egg is

iv. How it works: Pollen is picked up by a pollinator (birds/bees/etc) and transferred to another

plant, where it fertilizes an egg

b. Seed = embryo (baby plant) surrounded by a protective covering

i. Embryo: the baby plant

ii. Seed coat: the hard covering of the seed for protection

iii. Cotyledon: the food for the embryo; eventually becomes the first leaves of the plant

c. Dispersal

i. Other animals

ii. Wind

iii. Water

iv. Ejection

d. Germination

i. When a plant grows for the second time and pushes out of the seed

ii. Requires the right environment. Until the leaves are seen, it uses stored food to survive

3. Tropism – a change in growth direction due to an external stimulus (response)

a. Geotropism – movement or growth in response to gravity (stem grows up; roots grow down)

b. Phototropism – movement or growth in response to light (ex: a plant bending towards the light)

c. Thigmotropism – movement or growth in response to touch (growth towards the touch)

ORGANISM RELATIONSHIPS

1. Symbiotic Relationships

a. Mutualism

i. Both species benefit

ii.

iii. Example: dogs and humans (dogs get food/shelter; humans get companionship)

b. Commensalism

i. One species benefits, the other is neither harmed nor helped

ii.

iii. Example: clownfish and sea anemone (clownfish get protection; anemone isn’t affected)

c. Parasitism

i. One species benefits (parasite) and the other is harmed (host)

ii.

iii. Example: human and mosquito (mosquito gets blood; human gets an itchy spot)

d. Predation

i. One organism hunting and eating another

ii.

iii. Example: lion and gazelle (lion gets food; gazelle gets eaten/dead)

e. Competition

i. Two organisms fighting for the same resource(s)

ii.

iii. Intra-species example: two male deer fighting over the same female doe (mating)

iv. Inter-species example: a fox and a coyote fighting over the same rabbit for dinner

2. Food Chains and Food Webs

a. Each link in the food chain is known as a trophic level (transfer of energy between levels)

b. Only about 10% of the energy gets transferred from one level to the next; the rest is used or lost as heat

c. A food web shows all possible feeding relationships in a community at each trophic level (a network on

interconnected food chains)

d. Levels

i. Bottom: producers (autotrophs)

which have 100% of the total available energy

ii. Second level: primary consumers (herbivores)

which have 10% of the total available energy

iii. Third level: secondary consumers (omnivores

and/or carnivores) which have 1% of the total

available energy

iv. Fourth level: tertiary consumers

(omnivores and/or carnivores) which

have 0.1% of the total available energy

v. Only level NOT included in the pyramid:

decomposers, which break down dead

and decaying matter for energy

ECOLOGY AND SUCCESSION

1. Ecology = the scientific study of the interactions between organisms and their environments (focusing on energy

transfer)

a. Two factors make up environments

i. Biotic factor – all living organisms

ii. Abiotic factors – the non-living parts (temp, soil, water, light, air, etc)

b. Resources: all living organisms require four things to survive: food, water, space, and shelter

c. Carrying capacity: the maximum number of organisms that can be sustained by an environment

(populations of species fluctuate around the carrying capacity)

d. Limiting factor: controls the size of populations (water, food, competition, disease, number of

predator/prey)

2. Level of Organization (small to large):

a. Atom – the smallest component of an element

b. Molecule – a group of atoms bonded together

c. Organelle – the specialized structures of a living cell

d. Cell – smallest unit capable of performing life functions

e. Tissue – a group of cells working together to perform a specific function

f. Organ - a group of tissues working together to perform a major function

g. Organ System – a group of organs that work together to carry out life processes

h. Organism – any unicellular or multi-cellular form exhibiting the characteristics of life

i. Population – a group of organisms of one species living in the same place at the same time that

interbreed and produce fertile offspring. Compete with each other for resources

j. Community – several interacting populations in a common environment

k. Ecosystem – populations in a community and the abiotic factors with which they interact (biomes)

l. Biosphere – life supporting portions of Earth composed of air, land, fresh water, and salt water

3. Ecological Succession – the natural, gradual changes in the types of species that live in a certain area

a. Primary

i. Begins in a place with no soil (ex: sides of volcanoes, landslides, flooding)

ii. First lichens & moss grow on rocks, since they don’t need soil to survive (pioneer species)

iii. Lichens & moss break down rocks into smaller pieces. When they die, they decompose and add

organic matter to the rock to make soil. Then grasses grow to hold the newly made soil (so no

erosion). Once the soil layer is thick enough, wildflowers, shrubs, and other plants take over,

and animal begin to appear (first herbivores, then omnivores and carnivores)

1. Plant Progression: Lichen/moss grass flowers/shrubs small trees large trees

2. Animal progression: herbivores omnivores carnivores

iv. Ends in a climax community - a stable group of plants and animals that are the end result of the

succession process

b. Secondary

i. Begins in a place that already has soil and was once the home of living organisms (after forest

fires, flooding, tornados, etc.)

ii. Occurs faster and has different pioneer species from primary succession (pioneer = grass)

1. Plant Progression: Grass flowers/shrubs small trees large trees

2. Animal progression: herbivores omnivores carnivores

iii. Climax community – a stable group of plants and animals that are the end result of the

succession process