Biology Class 1

Question 1

What are the 4 relevant macromolecules?

Answer 1

Proteins
Lipids
Carbohydrates
Nucleic Acids

Question 2

How are macromolecules formed?

Answer 2

Through dehydration synthesis/condensation (join two monomers and get water removed)

Question 3

What are protein monomers?

Answer 3

Amino acids (20)

Question 4

What bond do 2 amino acids form?

Answer 4

Peptide bond

Question 5

Which direction does protein synthesis occur in?

Answer 5

N-C synthesis because amino acid is added on the C terminus

Question 6

What are the different protein structures?

Answer 6

Primary - a.a.
Secondary - alpha helix & beta pleated sheets (h-bonding between the backbone)
Tertiary - folding with side chain interactions WITHIN the polypeptide
Quaternary - Folding with side chain interactions BETWEEN different polypeptides

Question 7

What are carbohydrate monomers?

Answer 7

Monosaccharides

Question 8

3 Common Monosaccharides

Answer 8

Glucose
Fructose
Galactose

Question 9

3 Common Disaccharides

Answer 9

Maltose
Sucrose
Lactose

Question 10

What is the chemical formula of monosaccharides

Answer 10

C6H12O6

Question 11

3 Common Polysaccharides

Answer 11

Starch
Cellulose
Glycogen

Question 12

Difference between functions of carbohydrates and lipids

Answer 12

Short term energy storage vs long term storage

Question 13

What is the monomer structure of lipids?

Answer 13

Hydrocarbons

Question 14

What is a saturated fatty acid?

Answer 14

Maximimum number of hydrogens are attached

Question 15

What is a triglyceride formed with?

Answer 15

Glycerol molecule + 3 fatty acids

Forms ester bond through esterfication

Question 16

What is a phospholipid composed of?

Answer 16

Glycerol + phosphate + 2 fatty acids

Question 17

If a molecule has a polar & non-polar end, what is it called?

Answer 17

Amphipathic

Question 18

What is the function of phospholipid?

Answer 18

Formation of lipid bilayer thus, formation of lipid membrane

Question 19

What is a terpene composed of?

Answer 19

At least 2 isoprene units

Question 20

What is the function of terpenes?

Answer 20

Cholesterol

Formation of ear wax

Question 21

What is a terpenoid?

Answer 21

Modified version of terpene; vitamin A

Question 22

What are the functions of cholesterol & its derivatives?

Answer 22

Bile salts (to help with fat digestion)
Steroids
Cell membrame

Question 23

What is cholesterol composed of?

Answer 23

3 six -carbon rings + 1 five-carbon ring

Question 24

Thermodynamic Formula

Answer 24

ΔG = ΔH - TΔS
ΔH = PE
TΔS = KE

Question 25

Definitions of ΔG

Answer 25

ΔG = 0 means it’s in equilibrium
ΔG > 0 means it’s nonspontaneous, endergonic
ΔG <0 means it’s spontaneous, exergonic

Question 26

What is the energy of activation?

Answer 26

Amount of energy needed to produce transition state

Question 27

How can you make a reaction faster?

Answer 27

Add a catalyst which will decrease the energy of activation without changing ΔG & will stabilize the transition state

Question 28

What are 3 characteristics of enzymes as physiological catalysts?

Answer 28

1. Not used in reaction
2. Must increase reaction rate
3. Very specific in what they catalyse

Question 29

What is the first law of thermodynamics?

Answer 29

Energy is constant

Question 30

What is the second law of thermodynamics?

Answer 30

Entropy tends to increase
- ΔS= entropy decreases
+ ΔS=entropy increases

Question 31

Exergonic vs Endergonic

Answer 31

Exergonic (-) - energy is exiting system

Endergonic (+) - energy is added to system

Question 32

Endothermic vs Exothermic

Answer 32

Endothermic (+ΔH) - inputting heat

Exothermic (-ΔH) - liberating heat

Question 33

What are two ways enzymes can be turned on or off?

Answer 33

1. Phosphorylation
2. Allosteric Activator - turns on
   Allosteric Inhibitor - turns off

Question 34

What does Vmax depend on?

Answer 34

1. Type of enzyme

2. [E]

Question 35

What is Km

Answer 35

[S] required for 1/2 of Vmax

As affinity for [E] and [S] increases = Km decreases

Question 36

Competitive Inhibition

Answer 36

Binds at the active site
Vmax will stay the same
Km will increase

Question 37

Noncompetitive Inhibition

Answer 37

Binds at the allosteric site
Vmas will decrease
Km will stay the same

Question 38

Uncompetitive Inhibition

Answer 38

Binds at ES complex
Vmax will decrease
Km will decrease

Question 39

Mixed Inhibition

Answer 39

Binds at allosteric site
Vmax will decrease
Km will decrease (if binded to ES complex) or increase (if binded to enzyme alone)

Question 40

9 essential amino acids that cannot be synthesized by adult humans & must be obtained from diet

Answer 40

Lysine
Histidine
Threonine
Valine
Leucine
Isoleucine
Phenylalanine
Tryptophan
Methionine

Question 41

Purpose of reaction coupling

Answer 41

• Allows for generation of products that would not normally be formed spontaneously
• Reaction coupling allows for a spontaneous process to drive a nonspontaneous process to make the overall reaction spontaneous
• As this is affecting a thermodynamic property, it is unlikely to have an impact on kinetics (reaction rates would not increase, but would be limited by the slow reaction)

Question 42

What is a direct enzymatic regulation?

Answer 42

• Protein hydrolysis, phosphorylation/dephosphorylation, allosteric activity (even downstream) NOT modification of transcription factors

Question 43

What happens when a molecule covalently links to an enzyme site?

Answer 43

This would be known as an irreversible inhibitor; negligible enzyme activity

Question 44

How is dietary fat broken down?

Answer 44

Dietary fat is broken into 2 fatty acids and 1 monoglyceride prior to absorption. Due to the activity of lipase, triglycerides are broken down into two fatty acids and a monoglyceride before absorption and ultimate reassembly into a triglyceride in the enterocyte.

Question 45

Which linkage can be cleaved by human amylase?

Answer 45

B(1-6) (starch).

B(1-4) cannot & will pass undigested (cellulose)