Chapter 5.5 - ATP Production Flashcards Preview

Nutrition 120.3 > Chapter 5.5 - ATP Production > Flashcards

Flashcards in Chapter 5.5 - ATP Production Deck (19)
Loading flashcards...
1
Q

True or False: Lipids consumed in the diet can be used as an immediate source of energy.

A

True, they can also be stored in adipose tissue for future use.

2
Q

True or False: Triglycerides are continuously stored and broken down depending on the immediate energy needs of the body.

A

True. When the energy in the diet equals the body’s energy requirements the net amount of stored triglycerides does not change.

3
Q

What is the first step of the process to produce ATP from triglycerides?

A

Beta-oxidation, the carbon chain of fatty acids is broken into 2-carbon units that form acetyl-CoA and release high-energy electrons.

4
Q

What is oxaloacetate?

A

A 4-carbon molecule derived from carbohydrates.

5
Q

What must the acetyl-CoA combine with to enter the citric acid cycle?

A

An oxaloacetate to form a 6-carbon molecule called citric acid.

6
Q

Where are the high-energy electrons released in beta-oxidation and the citric acid cycle shuttled to?

A

The last stage of cellular respiration - the electron transport chain.

7
Q

What does the electron transport chain do?

A

Molecules in the chain accept electrons and pass them down the chain until they combine with oxygen to form water. The energy in the electrons is used to generate ATP.

8
Q

What does the reactions of the citric acid cycle produce?

A

Carbon dioxide (one carbon at a time).

9
Q

What happens when there is insufficient oxaloacetate?

A

Fatty acids cannot enter the citric acid cycle and ketone bodies form.
The glycerol from triglyceride breakdown can be used to produce ATP or glucose through gluconeogenesis.

10
Q

True or False: Glycerol makes up a large portion of the carbon in a triglyceride molecule, so lots of glucose comes from triglyceride breakdowns.

A

False. Glycerol makes up a small portion and the amount of glucose produced is small.

11
Q

What happens when carbohydrate is available for triglyceride metabolism?

A

Acetyl-CoA can enter the citric acid cycle, producing energy and carbon dioxide. The cycle can continue for as long as there is carbohydrates.

12
Q

What happens when carbohydrate is unavailable for triglyceride metabolism?

A

Ketones are produced which can be used for energy, excreted in urine, or accumulated in blood.

13
Q

Where does excess energy consumed as carbohydrates or protein first go?

A

To the liver where it can be inefficiently synthesized into fatty acids and transported to adipose tissue.

14
Q

How much can fat cells increase in weight by?

A

50 times increase.

15
Q

What happens when fat cells reach their maximum weight?

A

New fat cells can be synthesized.

16
Q

What can use ketones as an energy source?

A

Muscles and adipose tissue.

17
Q

How much of the body’s energy needs can be provided through ketones after days of starvation?

A

50%, the other half must be from glucose.

18
Q

What does the body break down to convert to glucose for energy for the brain?

A

Muscle proteins.

19
Q

What is the glucose/fatty-acid-cycle?

A

The inverse relationship between blood glucose and free fatty acids.