Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BMS07 > Metabolism Overview > Flashcards

Metabolism Overview Flashcards

1
Q

What is catabolism?

A

Metabolic breakdown of complex substances into smaller products

(Food –> building blocks + energy + heat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is anabolism?

A

Energy-requiring transformation of simpler substances into more complex ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why are substances broken down step-wise rather than all in one go?

A

Step-wise releases small, usable packages of energy

Each step has a smaller activation energy (all in one go = lots of energy wasted as heat and high Ea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why are forward and reverse pathways not direct opposites of each other?

A

Allows separate regulation

Prevents ‘futile cycle’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is another term for activated carrier molecules?

A

Cofactors

Coenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is energy stored at each step of an energetically favourable reaction?

A

To be used in energetically unfavourable reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What bonds in ATP are broken to release energy?

A

Phosphoanhydride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What properties make ATP suitable for energy storage in humans?

A

Chemically stable at physiological pH (6-9)

Structural features can be recognised by specific proteins, enzymes, etc

Hydrolysis releases energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does ΔG mean?

A

Change in free energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does it mean when ΔG is negative?

A

Energy released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the ΔG of ATP hydrolysis?

A

-31 to -50kJ/mol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is ATP hydrolysis energetically favourable?

A

Relieves electrostatic repulsion between phosphate groups (unstable molecule)

Released phosphate ion is resonance stabilised (electron delocalisation)

Increase in entropy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How much energy is release when ATP is hydrolysed to AMP + PPi?

A

Almost twice as much as ATP to ADP hydrolysis

As PPi spontaneously breaks down into two Pi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is PPi called?

A

Pyrophosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Give some of the functions of ATP

A

Cell motility and muscle contraction

Active transport

Metabolic control by regulating enzyme activity

Activate/phosphorylate molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What UTP used for?

A

Synthesis of complex sugars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is GTP used for?

A

Protein synthesis (translation)

Microtubule elongation

18
Q

Which activated energy carriers carry electrons and protons?

A

NAD(H)

NADP(H)

FAD(H2)

19
Q

What does acetyl coenzyme A carry?

A

Acetyl

20
Q

Which activated energy carrier carries a carboxyl group?

A

Carboxylated biotin

21
Q

What activated energy carrier carries a methyl group?

A

S-adenosylmethionine

22
Q

What activated energy carrier carries a glucose?

A

Uridine diphosphate glucose (UDP-glucose)

23
Q

What does NAD stand for?

A

Nicotinamide adenine dinucleotide

24
Q

What are the main differences between NAD+ and NADP+?

A

NADP+ has a phosphate group

NADP+ replaces NAD+ in anabolic reactions

25
Q

What happens molecularly when NAD+ is reduced?

A

Nicotinamide group accepts one H and an electron (leaving a spare proton)

26
Q

What does FAD stand for?

A

Flavin adenine dinucleotide

27
Q

What happens molecularly when FAD is reduced?

A

Flavin group accepts two H (added to nitrogens)

Originally neutral so no spare protons

28
Q

What type of bonds does coenzyme A form with carboxylic acids?

A

Thioester

29
Q

How do we write the structure of coenzyme A?

A

CoA-SH

30
Q

What are the three main stages of catabolism of sugars, fats and amino acids?

A

Conversion to acetyl unit

Krebs/TCA cycle

Oxidative phosphorylation

31
Q

What is pyruvate converted to in anaerobic respiration?

A

Lactate/lactic acid

32
Q

What is the structure of pyruvate?

A

-OOC–CO–CH3

33
Q

What enzyme catalyses anaerobic respiration?

A

Lactate dehydrogenase

34
Q

What is the purpose of anaerobic respiration?

A

Regenerate NAD+ so glycolysis can continue

35
Q

By what process is glucose converted to the acetyl unit?

A

Glycolysis

36
Q

By what process is a fatty acid converted to the acetyl unit?

A

Beta oxidation

37
Q

How is an amino acid converted to the acetyl unit?

A

Transamination

38
Q

How can regulation of metabolic pathways be achieved?

A

Changes in amount of enzyme (gene expression)

Changes in enzyme activity

39
Q

How can enzyme activity be altered?

A

Allosteric regulation/binding of allosteric regulators

Phosphorylation and dephosphorylation

40
Q

What kind of alteration to enzyme activity is instantaneous and local?

A

Allosteric regulation

BMS07 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions