Minimum Module 1 Review

Quarterly Assessment 1 ReviewBio Keystone Module A

BIO.A.1.1

• Explain the characteristics of life shared by all prokaryotic and eukaryotic organisms.

2. All need energy for metabolism.• Metabolism: All of the chemical processes in an organism that build up or break down materials.

What is shared by all living things?• An organism is any individual living thing.• Living things share some common characteristics:

1. All are made of one or more cells.

3. All respond to their environment.– Stimuli, or physical factors, include light, temperature,

and touch.4. All have genetic material (DNA) that they pass on to offspring.

Prokaryotic (no nucleus) & Eukaryotic (yes nucleus) Cells share certain characteristics.

1. Cells tend to be microscopic.2. All cells are enclosed by a plasma membrane. AKA Cell Membrane3. All cells are filled with cytoplasm.4. All cells have ribosomes. (can make proteins aka protein synthesis aka translation).5. All cells have hereditary material (DNA)

BIO.A.2.1• Describe how the unique properties of water

support life on Earth.• - Describe the unique properties of water and

how these properties support life on Earth (ex: freezing point, high specific heat, cohesion)

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Life depends on hydrogen bonds in water.

• Water is a polar molecule.– Polar molecules have slightly charged regions.

– Nonpolar molecules do not have charged regions.

1. Hydrogen bonds

form between slightly positive hydrogen atoms and slightly negative atoms. (oxygen)

Atom: OxygenCharge: Slightly negative

Atom: HydrogenCharge: Slightly positive

• Hydrogen bonds are responsible for important properties of water.– High Specific Heat: water resists changes in temp.

– Provides stability of temperature for land masses surrounded by water & for the temperature of the human body, & makes it an effective cooling agent.

– Cohesion: water molecules stick to each other. We saw this in the water lab when water built up on the penny & rolled around on the wax paper.

– Adhesion: water molecules stick to other things.– Ice floats on water: one of the only solids to float

on its liquid form – due to arrangement of water molecules due to charged regions.

Freezing Point • The freezing point is the temperature and

pressure at which a liquid material changes from a liquid to a solid. The freezing point of a liquid can be raised or lowered by adding other chemicals to it, such as by adding salt to water. Molecules slow down when forming a solid and pack tightly. Lipids(fats) tend to have a low freezing point.

Properties of Water (cont)Many compounds dissolve in water.

• A solution is formed when one substance dissolves in another. A solution is a homogeneous mixture.– Solvents dissolve other substances. (i.e. water)– Solutes dissolve in a solvent. (i.e. Koolaid powder)

solution

Properties of Water (cont)

– “Like dissolves like.”– Polar solvents dissolve polar solutes.– Nonpolar solvents dissolve nonpolar solutes.– Polar substances and nonpolar substances

generally remain separate.– Example: Oil (non-polar) and water (polar)

Maintaining homeostasis*Buffer: Helps to maintain pH.

Potential Hydrogen Affects Water

pH<7=Acid (more H+, less OH-)7=Neutral>7=Base (less H+, more OH-)

BIO. A.4.2• Explain the mechanisms that permit organisms

to maintain biological balance between their internal and external environments.

- Explain how organisms maintain homeostasis (ex: thermoregulation, water regulation, oxygen regulation).

Speaking of homeostasis…

• Homeostasis refers to your body maintaining stable, constant internal conditions.

• This may include:– Regulation of temperature (thermoregulation) Ex.: sweating

during exercise– Regulation of pH (buffers)– Regulation of oxygen delivery (for cellular respiration!). Ex:

heart beating faster during exercise– - Water regulation (iso, hyper, hypo tonic) osmoregulation -

regulation of water concentrations in the bloodstream, effectively controlling the amount of water available for cells to absorb.)

Feedback Loops• Feedback: Information from sensor that allows a control center to

compare current conditions to a set of ideal values.– Feedback loop: Sensorcontrol centertargetsensor….

• Negative feedback loops: control system counteracts any change in the body that moves conditions above or below a set point (reversing change to return conditions to their set points)-most functions in the body are regulated this way.– Ex.: Thermostats, holding your breath

• Positive feedback loops: Control center uses information to increase rate of change away from set points.– Ex.: Cut finger increases clotting factors in blood.

BIO.A.2.2• Describe and interpret relationships between structure and function at various

levels of biochemical organization (i.e., atoms, molecules, and macromolecules). • Explain how carbon is uniquely suited to form biological macromolecules. • Describe how biological macromolecules form from monomers. • Compare the structure and function of carbohydrates, lipids, proteins, and nucleic

acids in organisms.

Definitions

• Atom: The smallest unit of matter. Consists of a nucleus surrounded by electrons.

• Molecule: The smallest unit of an element or compound, made up of two or more atoms held together by strong chemical bond.

• Macromolecule: A large complex molecule, such as nucleic acids, proteins, carbohydrates, and lipids, with relatively large molecular weight.

Why Macromolecules? Because….Carbon atoms have unique bonding properties such as:

1. Carbon forms covalent bonds (strong bonds) with up to four other atoms, including other carbon atoms

2. They can form large, complex, diverse molecules

3. Carbon can form single, double, or triple bonds4. Carbon forms isomers

– Isomers are compounds that have the same chemical formula, but different structural formulas

• Example: C4H10

• Only carbon has these 4 characteristics

Carbon atoms have unique bonding properties – Slide 2

Many carbon-based molecules are made of many small subunits bonded together.

• Monomers are the individual subunits.• Polymers are made of many monomers.• When organisms break down large organic

compounds (macromolecules), they can obtain energy and/or put the monomers back together to form different compounds.

Carbohydrates

Monomer  monosaccharide

Polymer disaccharide (dimer), polysaccharide 

Examples Monosaccharide:  glucose, fructoseDisaccharide: sucrose (table sugar)

Polysaccharide: starch & cellulose (cell wall in plants),

glycogen (in animals)

Unique - Provide a quick source of energy

Lipids

Monomer  glycerol & fatty acids; polar heads & fatty acid tails

Polymer  triglycerides; phospholipidsExamples Fats, oils, cholesterol, steroids, waxes,

phospholipidsUnique - Nonpolar

- Broken down to provide energy- Used to make steroid hormones (control

stress, estrogen, testosterone)- Phospholipids make up all cell

membranes  - Fats and oils contain fatty acids bonded to

glycerol- Phospholipids make up all cell

membranes (keeps a cell fluid like, more heat = more flexibility in fluid)  

LIPIDS

ProteinsMolecule Proteins

Monomer Amino acid 

Polymer Polypeptide (protein) 

Examples Enzymes (catalyze biochemical reactions),  hemoglobin (transports oxygen in blood),

muscle movement, collagenUnique - 3D structure makes them active 

- Peptide bonds hold amino acids together- Have a side group (R) that makes each

amino acid (and therefore protein) different

- Sometimes may contain sulfur

Nucleic acidsMolecule Nucleic acids

Monomer  Nucleotide (5-carbon sugar, phosphate group, & base)

Polymer Nucleic acid 

Examples DNA & RNA 

Unique  - Order of the bases makes every living thing unique

- DNA stores genetic information- RNA builds proteins

Dehydration Synthesis

• Two monomers need to join to make a polymer.

Hydrolysis

• A polymer needs to break apart into monomers. Water is used to do this. (the carbs, proteins, and lipids we ingest are too big for us to use)

BIO.A.2.3• Explain how enzymes regulate biochemical

reactions within a cell. • Describe the role of an enzyme as a catalyst in

regulating a specific biochemical reaction. • Explain how factors such as pH, temperature,

and concentration levels can affect enzyme function.

Chemical reactions release or absorb energy.

• Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction

A catalyst lowers activation energy.• Catalysts are substances that speed up chemical

reactions– Decrease activation energy– Increase reaction rate

Enzymes allow chemical reactions to occur under tightly controlled conditions.

• Enzymes are catalysts in living things.–Enzymes are needed for almost all

processes.–Most enzymes are proteins.–Enzymes speed up reactions

without being consumed by increasing the reaction rate.

Disruptions in homeostasis can prevent enzymes from functioning.

• Enzymes function best in a small range of conditions.– Changes in temperature or pH, or

concentration levels can affect the rate of a reaction, also called DENATURING the enzyme.• An enzyme’s function depends on its

structure.

An enzyme’s structure allows only certain reactants to bind to the enzyme.

• Substrates: reactants that bind to an enzyme• Active site: area on the enzyme where substrates bind

Enzyme/Substrate Concentration

• Enzyme ConcentrationIf we keep the concentration of the substrate constant and increase the concentration of the enzyme, the rate of reaction increases linearly.

(That is if the concentration of enzyme is doubled, the rate doubles.)• Substrate ConcentrationIf we keep the concentration of the enzyme constant and increase the concentration of the substrate, initially, the rate increases with substrate concentration, but at a certain concentration, the rate levels out and remains constant

BIO.B.3.3• Apply scientific thinking, processes, tools, and

technologies in the study of the theory of evolution.

• Distinguish between the scientific terms: hypothesis, inference, law, theory, principle, fact, and observation.

1.3: Scientific Thinking & Processes

Key concept: Science is a way of thinking, questioning, and gathering

evidence.

• Science is a process of trying to understand the world around us using critical and logical thinking to evaluate results and conclusions.

• Scientists gather evidence and share their findings with one another.

• Observation: the use of our senses, computers, and other tools to gather information about the world.– Ex.: Studying the interactions between gorillas by

observing their behavior.

Observations can be recorded as data to be analyzed

• Qualitative data: Descriptions of phenomena that can include sights, sounds, and smells.

• Quantitative data: Characteristics that can be measured or counted such as mass, volume, and temperature; Numbers

Scientists use observations and data to form hypotheses

• Hypothesis: A proposed, testable answer to a scientific question.– Formal hypotheses are usually written in an “if,

then, because” format.– If (change of IV) then (change of DV) because (why

you think this will happen).

How do scientists test hypotheses?

• The scientific method– A) Observe and ask questions that lead to a

problem– B) Form a hypothesis – C) Test the hypothesis with a controlled experiment

by making observations and gathering data.– D) Analyze gathered data– E) Reject (start over at step B) or Accept your

hypothesis. – F) Form a conclusion

How do scientists test hypotheses?

• Controlled experiments study the effect of independent variables on dependent variables.

• Independent variable: A condition that is manipulated, or changed, by a scientist. Effects are measured by changes in dependent variables.

• Dependent variable: observed and measured during an experiment.– Example: Testing medication to treat blood pressure.

IV: medication dose, DV: blood pressure.

Controlled experiments

• Only one independent variable should be changed in an experiment.

• Other conditions must stay the same and are called constants.

• Controlled experiments must have a control group – everything is the same as the experimental groups but the independent variable is not manipulated.– Example: When testing blood pressure medication,

control group receives none of the active ingredient.• A large number of test subjects or trials is ideal.

Other important science terms• Inference: A conclusion reached on the basis of evidence and

reasoning. (Ex: you make an inference when you use clues to figure something out).

• Law: A law that generalizes a body of observations. At the time it is made, no exceptions have been found to a law. It explains things but does not describe them; serves as the basis of scientific principles. (Ex: Law of Gravity, Newton’s Laws of motion).

• Theory: A proposed explanation for observations and experimental results that is supported by a wide range of evidence – may eventually be accepted by the scientific community. (Ex: Big Bang Theory, Evolution & Natural Selection)

• Principle: A concept based on scientific laws and axioms (rules assumed to be present, true, and valid) where general agreement is present. (Ex: Buoyancy Principle)

• Fact: An observation that has been repeatedly confirmed.