Intermediary Metabolism 1 Flashcards

1
Q

Stability, balance, or equilibrium within a cell or body.

A

Homeostasis

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

The level or point at which a variable physiological state tends to stabilize.

A

Set point

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

Self-adjusting mechanism by the internal system

A

Feedback regulation

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

Two types of feedback regulation

A

Positive and negative feedback regulation

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

What are the three mechanisms of regulation?

A

Osmoregulation, Thermoregulation, and chemical regulation

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

What is positive feedback regulation?

A

Regulation that acts to speed up the direction of change.

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

What is negative feedback regulation?

A

Regulation that acts to reverse the direction of change to maintain the set point.

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

Which feedback regulation is the most common?

A

Negative feedback regulation

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

Name and explain the 3 types of osmoregulation solutions

A

1.Hypertonic solution- The solution outside the cell is more concentrated than the inside of the cell. Water will move out of the cell by osmosis, causing it to shrink.

  1. Isotonic solution- The solution inside the cell has the same concentration as the outside of the cell. Water will move in and out of the cell at an equal rate.
  2. Hypotonic solution- The solution outside of the cell has a lower concentration than the inside of the cell. Water will move into the cell by osmosis, sometimes causing it to burst.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name the six classes of enzymes.

A

1.Oxidoreductases
2. Transferases
3.Hydrolases
4.Lyases
5.Isomerases
6.Ligases

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

Explain what oxidoreductases catalyze

A

They catalyze oxidation-reduction reactions, which involves the loss or gain of protons.

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

Explain what reactions do transferases catalyze

A

They catalyze the transfer of a C-, N-, or P- containing groups.

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

Explain which reactions do hydrolases catalyze

A

Catalyze cleavage of bonds by addition of water.

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

What do lyases catalyze

A

Catalyze the cleavage of C-C, C-S and certain C-N bonds.

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

Which reactions do Isomerases catalyze?

A

Catalyze the racemization of optical or geometric isomers.

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

Which reactions do ligases catalyze?

A

Catalyze the formation of bonds between C and O, S, N coupled to hydrolysis of high energy phosphates.

17
Q

Name 4 catalytic strategies

A

Covalent catalysis
Acid-base reactions
Catalysis by approximating
Metal ion catalysis

18
Q

Briefly explain the covalent catalysis

A

In covalent catalysis, the enzymes covalently bond to the substrate as the first step.
The active sites contain a reactive group, that forms a covalent bond with the substrate.
Then, the enzyme goes through a mechanism, eventually breaking down the substrate and reforming itself.

19
Q

What occurs in acid-base reactions of enzyme-substrate?

A

The enzymes generally use a molecule other than water to donate or accept protons as a nucleophile.

20
Q

Briefly explain catalysis by approximation

A

The close proximity of two substrates can increase the rate of reaction between the two.
Generally, when two molecules combine to become one entropy decreases.
An enzyme that brings the two molecules together decreases the entropy.
This increase in rate is similar to increasing the concentration of the reactants.

21
Q

Briefly explain metal ion catalysis

A

Metal ions can directly facilitate the formation of bonds.
They are electrophilic and can also act to stabilize the charges on the intermediates in the reaction.

22
Q

What are holoenzymes, and differentiate between holoenzymes and apoenzymes.

A

Holoenzymes are the enzymes that require molecules other than proteins for enzymic activity.

Holoenzyme- is active with its nonprotein compenent.
Apoenzyme- is inactive without its nonprotein component.

23
Q

Name three factors that affect enzyme function

A

-Substrate concentration
-Temperature
-pH

24
Q

By definition, what is Km?

A

Km is the substrate concentration at which the velocity is half of the maximum velocity.

25
Q

Name and describe the two types of inhibitor.

A

Irreversible inhibitors- binds to enzyme through covalent bonding.
Reversible inhibitors- binds to the enzyme through non-covalent bonding.

26
Q

Name two types of reversible inhibitors

A

Competitive and non-competitive

27
Q

Briefly explain the two types of reversible inhibition and how they affect Vmax and Km.

A

Competitive inhibition- the inhibitor binds to the active site of the enzyme, preventing the substrate from binding.
In competitive inhibition Km increases while Vmax remain the same.

Non-competitive inhibition- the inhibitor binds to a different site ( allosteric site) other than the active site of the enzyme, changing the conformation of the active site.
In non-competitive inhibition the Vmax decreases while Km remains the same.

28
Q

Name and explain the two types of allosteric inhibition.

A

Negative feedback loop, allosterically inhibits the production of a substrate.

Positive feedback loop, allosterically increases the production of a substrate by acting as a cofactor or coenzyme.