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Flashcards in Biochemistry Basics Deck (40)
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1
Q

This is the transfer and use of energy in biologic systems.

A

Bioenergentics

2
Q

This term refers to a change in free energy.

A

ΔG

3
Q

ΔG approaches zero as the reaction approaches what?

A

Equilibrium

4
Q

This is a change in heat content of the reactants and products.

A

Enthalpy

5
Q

This is a change in randomness/disorder of the reactants and products.

A

Entropy

6
Q

When ΔG is ___ the reaction proceeds, is exergonic, and implies a net loss of energy

A

Negative

7
Q

When ΔG is ___ the reaction does not proceed, is endergonic, and implies a net gain of energy.

A

Positive. Energy must be added to the system to make it proceed.

8
Q

When ΔG is ___ reactants are at equilibrium.

A

Zero

9
Q

The free energy changes (ΔG) are ____ in any sequence of consecutive reactions.

A

Additive

10
Q

As long as the sum of ΔG’s of the individual reactions is ____, the pathway moves forward.

A

Negative

11
Q

This is when two reactions are happening at the same time.

A

Coupled reaction. The net ΔG must be negative for the reaction to occur.

12
Q

This common reaction is characterized by the adding/removing of a phosphate group.

A

Phosphorylation

13
Q

During phosphorylation, these enzymes add phosphate groups.

A

Kinases

14
Q

During phosphorylation, these enzymes remove phosphate groups.

A

Phosphatases

15
Q

This common reaction is characterized by the rearranging of atoms.

A

Isomerization

16
Q

During isomerization, this enzyme rearranges atoms.

A

Isomerases

17
Q

This common reaction is characterized by shifting a group on a molecule.

A

Mutation

18
Q

During mutation, this enzyme shifts a group onto a molecule.

A

Mutases

19
Q

This common reaction is characterized by the building of something.

A

Synthesis

20
Q

During synthesis, these enzymes are used to build structures.

A

Synthases or synthetases

21
Q

This common reaction is characterized by the oxidizing or reducing of something.

A

Redox

22
Q

During redox, what enzyme is typically used.

A

Dehydrogenases. They are named after what they oxidize

23
Q

Enzymes allow reactions to happen at ____ energies.

A

Lower

24
Q

This common molecule is a derivative of niacin (B vitamin) and both accepts and donates electrons.

A

NAD

25
Q

This common molecule is a derivative of riboflavin (B vitamin) and both accepts and donates electrons.

A

FAD

26
Q

This common molecule is a derivative of pantothenic acid (B vitamin), holds and transfers acetyl or acyl groups, and creates a “thioester bond”

A

Coenzyme A (not a true enzyme)

27
Q

What is the role of NADH + H+ and FADH2?

A

All they do is accept and donate electrons

28
Q

How much energy does the removal of a phosphate group from ATP generate?

A

7.3 kilocalories

29
Q

The presence of AMP stimulates a powerful enzyme called what?

A

AMPkinase

30
Q

What does AMPK stimulate?

A

GLUT4, glycogen breakdown, glycolysis, fat burning, and LPLm activation

31
Q

What does AMPK inhibit?

A

Glycogen synthesis, TAG synthesis, cholesterol synthesis, and fatty acid synthesis

32
Q

In general, what does a high energy charge tell a cell to do?

A

It tells it to build things (fat, glycogen, glucose, cholesterol, nucleotides)

33
Q

In general, what does a low energy charge tell the cell to do?

A

Create ATP (glycolysis, fat oxidation, aminoacid oxidation, Kreb’s cycle)

34
Q

When the bond between ATP’s phosphate groups is broken, relatively large amounts of free energy are released. How much free energy is released?

A

ΔG=-7.3kcal/mol

35
Q

To recreate ATP we have to get energy from molecules that can release (greater or lesser) than 7.3 kilocalories.

A

Greater

36
Q

During enzyme regulation, what occurs to the enzyme when there is excess product? By what mechanism does this occur?

A

The enzyme is inhibited when there is excess product through the mechanism of enzyme inhibition. When there is scarce product the enzyme is stimulated.

37
Q

During enzyme regulation, what occurs to the enzyme when there is excess reactant? Scarce reactant? By what mechanism does this occur?

A

The enzyme is stimulated when there is excess reactant through the mechanism of mass action. When there is scarce reactant the enzyme is inhibited.

38
Q

This hormone is secreted in response to high blood glucose. It lowers blood glucose to baseline values and increases glucose in fat and muscle cells.

A

Insulin

39
Q

This hormone is secreted in response to low blood glucose and increases blood glucose levels. It causes the liver to release glucose from storage (glycogen) and to make glucose (gluconeogenesis).

A

Glucagon

40
Q

These hormones are involved in the flight or flight response.

A

Epinephrine and norepinephrine