Review 13 Flashcards Preview

Review > Review 13 > Flashcards

Flashcards in Review 13 Deck (36):
1

Structure of threonine

Same as serine except OH and CH3 both come off CH2

A image thumb
2

How can you break a peptide bond?

Add strong base

3

Conjugated protein

Proteins w/ covalently attached molecules

 

- Attached molecule = prosthetic group (metal ion, vitamin, lipid, carbohydrate, nucleic acid)

4

Mixed inhibition = inhibitor binds to E and ES w/ (equal/unequal) affinity

Unequal

5

Enzyme devoid of necessary cofactor = ______

Apoenzyme 

- Catalytically inactive

6

Lyase

Breakdown of single molecule into two molecules

- Often forms cyclic compounds or double bonds

- Does not add water and does not transfer electrons

7

Ligase

Joins two large biomolecules together

8

Epimer

 

Anomer

Epimer = subtype of diastereomers that differ at exactly 1 chiral carbon

 

Anomer = subtype of epimer that differ at anomeric carbon

9

Number of glucose chiral centers

4 => 16 stereoisomers

Aldohexose

A image thumb
10

React ethanol w/ glucose => ?

Glycoside

- Replace hemiacetal w/ acetal

A image thumb
11

Beta-amylase

 

Alpha-amylase

Beta-amylase = cleaves maltose at non-reducing end => maltose exclusively

 

Alpha-amylase = cleaves maltose anywhere => maltose, glucose, and polysaccharides

12

Reducing sugar

Any sugar w/ hemiacetal ring

- Has free aldehyde group or ketone group (that can tautomerize)

- One anomeric carbon in molecule is NOT involved in anomeric bond and is free to be oxidized under H2O/Br => forms acetal/ketal

- Ex. all monosaccharides b/c all have aldehyde group, maltose, lactose, cellobiose

13

Amylose

 

Amylopectin

Amylose = linear, all alpha 1-4

 

Amylopectin = has branches, alpha 1,6

14

Hemiacetal vs. Acetal

Hemiacetal has OR, H, R, and OH group (like monosaccharides)

Acetal has no OH group but OR, H, R and OR group (polysaccharides)

A image thumb
15

One terpene = ____ isoprenes

One terpene = 2 isoprenes

16

Prostaglandin

Autocrine + paracrine hormones that regulate cAMP

17

Saponification = ______ hydrolysis of triacylglycerol using strong ______

Ester hydrolysis using strong bases

18

Triacylglycerols

Highly hydrophobic

Does not get hydrated => does not have extra weight on it (which would take away energy density)

Highly reduced => can produce more energy

19

More saturated fatty acids => (more/less) fluid solution

Less fluid b/c can pack more tightly and form more noncovalent bonds

- Higher melting point for saturated than unsaturated

20

How do you hydrolyze an amide?

Add H2O and heat to form COOH from amide

A image thumb
21

Fructose structure

6 carbons => forms 5 carbon ring (furanose)

- Ketohexose

A image thumb
22

Is longer DNA more/less stable?

More stable b/c more H bonds throughout

23

Unfolding of proteins = (cooperative/noncooperative) => shape of curve is ________

Cooperative => sigmoidal

24

Non-reducing sugar

Cannot be oxidized b/c no hemiacetal/hemiketal present

- Both anomeric carbons are involved in anomeric bond

- Ex. sucrose (glucose + fructose)

25

Peptidyl transferase

Catalyzes formation of peptide bond b/w incoming AA and growing polypeptide chain

26

What does RNA Pol I do and where is it?

Located in nucleolus

Transcribes rRNA

27

Compounds that contribute to membrane fluidity do what?

Lower melting point or disrupt crystal structure

- Ex. cholesterol, unsaturated lipids

28

Which glycolysis enzymes catalyze irreversible reactions?

 

What enzymes are used instead in gluconeogenesis and what are they activated by?

Glucokinase (liver) and hexokinase (muscle), PFK-1, and pyruvate kinase

 

Gluconeogenesis:

  • Pyruvate carboxylase - converts pyruvate to OAA => PEP
    • Activated by acetyl CoA
  • Fructose 1,6 bisphosphatase - converts F16BP to F6P
    • Activated by ATP and glucagon
  • Glucose 6 phosphatase - converts G6P to glucose
    • Only found in ER of liver

29

Pyruvate dehydrogenase is stimulated by _____ and inhibited by _______

Stimulated by insulin

Inhibited by Acetyl Co-A

30

What does glycogen synthase do?

Creates alpha 1-4 glycosidic linkages b/w glucose molecules

- Activated by insulin in liver and muscle

31

Glycogen phosphorylase

Breaks alpha 1-4 links b/w glucose in glycogen => catalyzes glycogen breakdown

- Activated by glucagon when glucose is gone

32

Pentose-phosphate pathway rate-limiting enzyme

Glucose-6-phosphate dehydrogenase

- Activated by NADP+ and inhibited by NADPH and insulin

33

Pyruvate can form what three molecules?

Lactate (fermentation)

OAA (gluconeogenesis via pyruvate carboxylase)

Acetyl-CoA (TCA via pyruvate DH)

34

What does citrate regulate?

Negative allosteric regulator of PFK1 (which catalyzes rate-limiting step of glycolysis)

35

What does pentose phosphate pathway do?

Generates NADPH using G6PDH => reduces glutathione (antioxidant)

- PPP mitigates oxidative stress

- NADPH also synthesizes lipids/cholesterol, produces bleach in lysosomes in addition to mitigating oxidative stress

36

Name the rate-determining enzymes for:

- Glycolysis

- Gluconeogenesis

- PPP

- Glycogenesis

Glycolysis = PFK1

Gluconeogenesis = F16BP

PPP = G6P dehydrogenase

Glycogenesis = glycogen synthase