Biology 067 -Final Review of Sections 1 to 9: Molecules of life, Cell structure and function, tissues,
digestion, urinary system, cardiovascular system, blood, Defence against disease.
Sectn 1: Molecules of Life
Atoms to Molecules
A covalent bond = electrons are shared between 2 atoms
An ionic bond = an attraction of charged atoms
Water and living things
Hydrogen bond = the attraction of a slightly positive covalently bonded H to a slightly negative
atom in the vicinity (usually oxygen)
Macromolecules
Macromolecules are made by joining smaller molecules (monomers) together to form longer
chains called polymers – this is done through a reaction called dehydration synthesis.
Hydrolysis is the reverse, it breaks down the polymers back into subunits.
Carbohydrates
Subunit of carbohydrate = monosaccharide
All carbohydrates are composed of C,H, and O
Monosaccharide’s dehydration reaction form polysaccharides
Starch is a type of carbohydrate
Lipids
Subunits of lipids = glycerol and 3 fatty acids
a specialized lipid is a phospholipids =glycerol, phosphate, 2 fatty acids –the phosphate group
replaces one of the fatty acids
Proteins
The subunit of a protein=amino acid
aa always have an amino group (NH2) and an acidic group (COOH)
Amino acids form a polypeptide thru dehydration rxn
aa joined by a peptide bond
H
The 4 levels of protein structure: primary, secondary, tertiary, quaternary
Level Shape Bonding
Primary Linear chain of aa Peptide bonds between aa
Secondary Helix (coiling) Pleated sheet (folding)
Hydrogen bonds between aa
Tertiary globular Final 3D shape and function: Ionic, covalent, hydrogen bonds btwn R groups
Quaternary (rare) All shapes All bonding – 2 or more associated polpeptides
Denaturation = changing the 3 dimensional shape of proteins – often caused by extremes in
heat or pH
Nucleic Acids
Nucleic acids are DNA and RNA
Subunit of nucleic acids =nucleotides
nucleotide =phosphate group, sugar, nitrogen base
ATP is a specialized nucleotide
ATP = nucleotide that carries energy in a high-energy phosphate bond – when that bond breaks,
energy is released
ATP = adenosine + 3 phosphate groups (adenosine=adenine + ribose a sugar)
Section 2: Cell structure and Function
Know function of various cell organelles – on diagram in text or in notes
Plasma membrane
The plasma membrane:
boundary between cell and its environment
determine which substances enter and leave a cell
contains receptor sites which determine how cell interacts with its environment
has proteins embedded in the plasma membrane
plasma membrane has:
hydrophilic heads face outside (and inside) the cell
hydrophobic tails face interior of membrane
Means of transport across the plasma membrane
Passive:
diffusion = movement of molecules from area of hi concentration to area of low concentration
osmosis - movement of water molecules from area of hi concentration to area of lower
concentration
facilitated transport - requires a concentration gradient and a protein carrier
Active
active transport – requires a carrier and energy
endocytosis occurs when a vesicle is formed (Stuff coming in)– the cell membrane invaginates
and engulfs something –transporting a large molecule inside via a vesicle
Exocytosis – transporting a large molecule to outside via a vesicle (stuff going out).
Nucleus and endomembrane system
after processing and modifying proteins and synthesizing phospholipids - ER forms vesicles to
transport proteins (from RER) and phospholipids (from smooth ER) to other parts of the cell
including the golgi
both SER and RER form vesicles
the golgi apparatus = packaging centre to get cell products ready for export
The lysosome = a vesicle with digestive enzymes for intracellular digestion
Mitochondria and cell metabolism
Mitochondria =primary source of ATP
Cell respiration in mitochondria (aerobic)
Section 3: Tissues There are 4 types of tissue:
1. Connective: binds structures together - provides structural support
2. Muscle: moves body and its parts
3. Nervous tissue -specialized for conduction of impulses
4. Epithelial: covers body surfaces and lines cavities
1. Connective tissue = a.Fibrous, b.Supportive, c.Fluid
3 major components of all connective tissue = cells, ground substance, protein fibers
a. Fibrous (=Loose, adipose and dense)
1.Loose –supports epithelium and lines organs
2.Adipose – specialized loose – stores fat for energy, protection and insulation
3.Dense: tendons – connect muscle to bone
Ligaments – connect bone to bone at joints
b.Supportive (= cartilage and bone)
Cartilage: solid but flexible 3 types
1.Hyaline cartilage- found at end of long bones, nose, ribs, and respiratory passages
(trachea)
2. Elastic cartilage – more flexible – i.e outer ear
3.Fibrocartilage – can withstand great pressure and tension – found between vertebra
and cushions in the knee joint
Bone
1. Compact bone – rigid CT –shafts of long bone
2. Spongy bone – ends of long bones and surrounding the bone marrow cavity – contains
red bone marrow where red blood cell are produced
c. Fluid (=blood and lymph)
1.Blood – has a fluid matrix –
o transports oxygen and nutrients to cells,
o removes CO2 and wastes from cells,
o distributes heat, and
o protects against disease.
2.lymph –tissue fluid with WBC
o Absorbs fat molecules, excess tissue fluid and solutes
o WBC engulf pathogens
2. Muscle tissue
Skeletal Smooth Cardiac
Location Muscles attached to skeleton
Around tubes (viscera and blood vessels)
heart
Function Movement of body parts
Moves “stuff” thru tubes
Heart beat pumps blood thru body
Appearance Striated Spindle shaped Branching and interconnecting
Nervous control Voluntary Involuntary involuntary
3. Nervous tissue Made up of neurons and neuroglia
Neurons have 3 parts:
1. Dendrites –receives input
2. Cell body –organelles, cytoplasm and nucleus
3. Axon – sends nerve impulses
4. Epithelial tissue
1. Simple epithelial: single layer - lining of organs - aids in absorption, protects, allows
exchange
2. Stratified epithelial: layers of cells – outer layers – protection
3. Glandular epithelium– exocrine gland (contain ducts)and endocrine glands (ductless)
secretes a product – can be single celled or as a gland
Body cavities, membranes
Cavities of the body: Dorsal (back) and ventral (front) cavities
Dorsal cavity has 2 parts: cranial and vertebral cavities
Ventral cavity into 3: thoracic, abdominal and pelvic
4 types of membranes
1. Mucous – lines the external openings of body, and in digestive, urinary and reproductive
systems
2. Serous – lines the thoracic and abdominal cavities
1) Pleura – lines thoracic cavity and covers lungs
2) Pericardium – covers heart
3) Peritoneum – lines abdominal cavity
3. Synovial –lines cavities of joints
4. Meninges –surrounds the brain and spinal cord
Section 4: Digestive system (sectn 5 macromolecules lumped in earlier)
Path of food: mouth> pharynx> esophagus> stomach> small intestine > large intestine > rectum > anus
2 types of digestion
1. Mechanical –chew and mixing food –mouth and churning of food in stomach
2. Chemical – enzyme breaks down macromolecules into subunit molecules
Functions of Parts of the digestive tract:
Mouth - mixes food with saliva, forms chewed food into a bolus for swallowing
Pharynx – back of throat – at base of pharynx you have epiglottis which is a flap that covers
trachea which stops food from going down the trachea and into lungs
Esophagus – no digestion or absorption –uses peristalsis to move food down to stomach –
rhythmic contractions of the digestive tract
-has sphincter – which is muscles that encircle a tube – between esophagus and stomach – acts
like a door
Stomach – primary functions are = store food, churn it up and begin digestion – churns food
into “stomach soup” called chyme which is very acidic – mucus protects stomach wall
- pepsin –which begins digestion of protein gastric glands in stomach make gastric juice which
has pepsin, and
- HCL which kills bacteria, breaks down connective tissue, and activates pepsin
Small intestine –main nutrient absorption, has a neutral pH,
-Duodenum – 1st 25 cm of SI – receives thru ducts:
-bile from liver and gall bladder - emulsifies fat
-Pancreatic juice from pancreas – neutralizes chyme and has enzymes
Large intestine – mainly Absorbs water, but also absorbs salts, vitamins, stores and gets rid of
indigestible
Regions: cecum, colon, rectum
Parts of the colon: ascending, transverse, descending and sigmoid
Digestive enzymes and the breakdown of starch, proteins, nucleic acids and lipids
Macro molecule
Enzyme Breakdown products
Enzyme (SI) Breakdown products
Carbo hydrates
Salivary amylase (mouth)
Maltose Maltase glucose
Pancreatic amylase (SI)
Maltose Maltase glucose
Protein Pepsin (stomach) Peptide Peptidase Amino acids
Trypsin (SI) Peptide Peptidase Amino acids
Nucleic acids Nuclease (SI) Nucleotides nucleosidase 5 C sugar + phosphate + nitrogen base
Lipid Enzyme title n/a Bile emulsifies the
fat (SI)
Lipid droplets lipase Glycerol + fatty acids
Accessory Organs
A. Pancreas
- secretes hormones functions as endocrine gland –– keeps blood glucose levels normal
Endocrine= ductless – secretes into the bloodstream directly
- secretes pancreatic juice via a duct to the small intestine –acts as exocrine gland –
Pancreatic juice contains sodium bicarbonate (neutralizes chyme) and digestive enzymes: pancreatic
amylase to digest starch/trypsin digests proteins/ lipase digests fats (after emulsification by bile)
B. Liver – largest organ,
1. monitor blood –keeps blood contents constant – removes poison, detoxifies blood.
2. Removes and stores iron, vitamin ADEK
3. Makes plasma proteins from AA
4. Maintains blood glucose
If Excess glucose in blood in hepatic veinstored in liver as glycogenbroken down as
neededagain...excess glucose in blood in hepatic vein etc...
If glycogen stored in liver is depleted, liver converts glycerol (from fat) and AA to glucose
5. Produces urea after breaking down aa
6. Produces bile – stored in gall bladder used to emulsify fat – breaks fat into tinier fat droplets,
increases surface area for lipase activity
7. Makes lipids from fatty acids helps regulate the quantity of cholesterol in blood.
C. Gall bladder
Attached to surface of liver
Stores excess bile produced by liver
Bile leaves gall bladder and moves to duodenum by common bile duct
Section 6: The Urinary System
Organs of the Urinary system
Kidneys
Ureters -Connects kidneys to bladder
Bladder -Stores urine until it is expelled
Urethra Small tube that connects bladder to exterior of body
3 main Functions of the Urinary system:
Excretion of metabolic waste: urea, uric acid, creatinine, ammonium
o Urea – end product of amino acid breakdown otherwise known as protein breakdown -
occurs in the liver
o Uric acid – formed from breakdown of nucleotides
o Creatinine – nitrogen waste formed from the end product of creatine phosphate
breakdown (which is a hi energy reserve molecule in skeletal muscles)
o Ammonium –produced as a less toxic form of ammonia
Maintenance of salt/water balance
o Regulates blood pressure by regulating blood volume
o Maintains the level of other ions in the blood
Maintenance of acid-base (pH) balance
o pH of blood ~7.4 -kidney monitors blood pH and regulates it by excreting H+ (acid) and
reabsorbing HCO3- (base) as needed
Urinary system also contributes to hormonal function Secretes erythropoietin (hormone) to increase
RBC production if O2 carrying capacity of blood decreases
o Secretes renin, an enzyme that stimulates the release of hormones to regulate the salt/water
balance of blood
Kidney structure Microscopic Structure
Blood supply:
Renal artery afferent arteriole glomerulus (knot of capillaries) efferent arteriole
peritubular capillary network venule renal vein
Parts of the nephron:
Glomerular capsuleproximal convoluted tubuleloop of nephrondistal convoluted
tubulecollecting ducts (in renal medulla -not part of nephron)
Urine Formation
Three steps or processes...
1) Glomerular filtration – in glomerular capsule
o Renal artery enters kidney -afferent arterioles branch off the renal artery –you have millions of
these afferent arterioles going off to their nephrons...
o Whole blood enters glomerulus through the afferent arteriole
o Due to increases blood pressure, H2O and small molecules move to inside of glomerular capsule
– these small molecules = glomerular filtratate the rest of the blood and its contents stay in the
blood stream
o Glomerular filtrate = water, nitrogenous waste, nutrients, salts
2) Tubular reabsorption: in proximal and distal convoluted tubule but mostly proximal convoluted
tubule
Molecules and ions are passively and actively reabsorbed from nephron back to blood in
peritubular capillary network
o Reabsorption from nephron to blood
o When Na+ ions -actively reabsorbed, chloride ions passively follow
o Reabsorption of salt increases osmolarity of blood compared to filtrate -so H2O moves
passively from tubule to blood
o Glucose and aa also reabsorbed from proximal convoluted tubule to blood –glucose should
not be in urine – if it is, possible sign of diabetes.
o What goes back into the blood: most of the water, nutrients, required salts as well as glucose
and aa
3) Tubular secretion –occurs along the length of kidney’s convoluted tubules but mostly in distal
convoluted tubule
o Second way that substances are removed from the blood and actively added to tubular fluid. -
1st way is glomerular filtration
o i.e. Hydrogen ions (H+), creatinine, and excess drugs such as penicillin -examples of some of the
substances moved by active transport from blood into the convoluted tubules.
Section 7: Cardiovascular system: heart and blood vessels
Blood vessels:
3 Types of blood vessels:
1. Arteries, arterioles -away from heart, O2 rich (except pulmonary)
2. Capillaries – gas and nutrient/waste exchange
3. Veins, venuoles – to the heart, O2 poor (except pulmonary)
Summary table:
artery capillary vein
Blood pressure Hi Low lowest Valves present or absent
Absent Absent Present
Wall thickness 3 layer 1 cell 3 layer function Take blood away from
heart Exchange of O2/CO2, nutrients/waste
Take blood to heart
arteries -oxygenated blood except: pulmonary artery
veins -deoxygenated blood except: pulmonary veins
capillaries: Arterial end, BP>OP/ midway BP=OP / venous end BP<OP
Mechanisms that aid with venous blood flow:
1. Skeletal muscle contraction
2. Pressure changes in the thorax due to respiratory movements
3. One way valves in veins
Heart Valves:
heart valves: prevent backflow
Btwn rt atrium - rt ventricle: tricuspid valve
Btwn lft atrium - lft ventricle: mitral valve (bicuspid)
rt ventricle- pulmonary trunk: pulmonary semi-lunar valve
lft ventricle -aorta: aortic semi-lunar valve
String like structures that anchor AV valve: chordae tendineae
**review order of passage of blood thru heart (diagram)
Control of the heartbeat:
The 2 sides of the heart are separated by: the septum
Systole: working phase –includes the contraction of the atrium and ventricles
Diastole: relaxation phase
Both systolic and diastolic pressure decrease with distance from left ventricle
Intrinsic (internal) control of HB:
1. Electric impulse starts in the SA node found in upper rt wall of atria
2. Both atria contract
3. Impulse then travels to AV node at base of rt atrium
4. Impulse travels down AV bundle to Purkinje fibres - ventricles contract from the
bottom up
Extrinsic control:
cardiac control centre of brain (medulla oblongata)– can cause HB to increase for flight or
fight, or decrease for normal resting
Cardiovascular pathways
1. Pulmonary circuit:
2. Systemic circuit
System that begins at intestine and flows through liver and monitors blood= hepatic portal
system
Section 8: Cardiovascular system: Blood
Functions of the blood:
1. Transport
2. Defence
3. Regulation
Composition of blood:
1. Formed elements= RBC, WBC, Platelets
2. Plasma = is composed of: water, hormones, gases (CO2 and O2), ions, vitamins, nutrients,
wastes, plasma proteins
RBC:
Transport O2 and CO2 (CO2 some of the time)
Small, biconcave and have no nucleus
Hemoglobin in RBC carries O2
Hemoglobin that carries excess H+ ions (on its way back to lungs to collect more oxygen)called
reduced hemoglobin
WBC:
Can leave bloodstream to get to area needed
5 different types of WBC and their function:
Type Function
neutrophil 1st responders, phagocytotic rxn Basophil Allergic rxn response Eosinophil Parasitic worm infection Monocyte Phagocytotic lymphocyte B cell: antibodies against bacteria antigens
T cells: cytotoxic T cells against viruses and cancer
Some defntns to remember:
Pathogens = microscopic infectious agents such as bacteria and viruses which are capable of
causing diseases = any foreign substance that stimulates the immune system
Antigen = molecules found on invading pathogens that allow them to be recognized
Platelets:
Needed for blood clotting along with clotting proteins – clump at puncture site
Section 9: Lymphatic system and immunity:
Lymphatic organs:
1. Red bone marrow - active Red bone marrow in an adult is located: skull, sternum, ribs, pelvic
bones, end of long bones.
2. Thymus
3. Spleen
4. Lymph nodes
5. Tonsils
6. Peyers patches – in small intestine
7. Appendix
Immune barriers to entry:
1. Skin
2. Oil glands – secrete chemical to kill bacteria on skin
3. Cilia – in upper respiratory tract
4. Mucous – in upper respiratory tract
5. Local area bacteria in intestine
6. Acidic ph - in stomach acid – kills bacteria
Non specific defences:
1. Barriers to entry: skin, mucous, oil, stomach acid
2. Inflammatory reaction –allows phagocytotic cells to enter tissue fluid to attack pathogens
3. complement proteins =complement system also called =Protective proteins
Complement kill foreign microbes by: causing them to burst
4. Phagocytes and natural killer cells – neutrophils and monocytes (macrophages) engulf and
destroy pathogens. NK (natural killer cells) cells release perforin and inject granzymes (similar
to how cytotoxic T cells kill pathogens) into pathogen
Specific defences:
Effective against a particular infectious agent
Immune system distinguishes self from nonself
B cells:
B lymphocytes develop in the bone marrow
Represent a specific response
Are part of an antibody-mediated immunity
Protein released by B cells= antibodies
Antibodies are proteins released from plasma cells (B cells) to fight infections
Unlike T cells, B cells DO NOT require antigen-presenting cell
T cells
Lymphocytes travel to the thymus to become mature T lymphocytes
T cells recognize antigens because they are activated by antigen presenting cells
Cytotoxic T cells produce perforin to punch holes in invading pathogen
Apoptosis =programmed cell death (PCD) once the threat of infection passes – development of
new plasma cells stop and those present undergo apoptosis because they are no longer needed
Comparison of specific immune responses between B cell and T cell immunity:
B cell T cell
Where produced Red bone marrow Red bone marrow Where mature Red bone marrow Thymus Type of mediated response Antibody mediated response Cell mediated response Antigen recognition mechanism
B cell receptor recognizes nonself
Antigen presenting cells
response -Clonal expansion to form plasma cells to produce antibodies -Memory B cells
-Cytotoxic T cells -helper T cells to help B cells -memory T cells
Acquired immunity:
Active
Long lasting
Either produced by own body or induced by vaccines Passive
Temporary
Individual given prepared antibiotics
Antibodies in mother’s milk = example of passive immunity