Exam 4: Lecture 61: Liver phys 1

Question 1

The rate of absorption of nutrients from the GIT (is/is not) constant.

Answer 1

Is not

Question 2

What are the metabolic fuels for homeostasis?

Answer 2

GLucose, amino acids, fatty acids, ketone bodies

Question 3

Where does majority of gluconeogenesis occur?

Answer 3

Liver

Question 4

Which pathway of pyruvate allows flow in either direction and can synthesize glucose through gluconeogenesis?

Answer 4

Pyruvate + oxaloacetate

Question 5

T/F: Once pyruvate is converted to acetyl-CoA it can revert to pyruvate with a different enzyme.

Answer 5

False - once it is acetyl-CoA it is irreversible

Question 6

What type of amino acids are substrates for gluconeogensis?

Answer 6

Glucogenic amino acids

Question 7

How are fatty acids stored in adipose tissue?

Answer 7

As triglycerides

Question 8

What is a major difference between fatty acids and ketone bodies?

Answer 8

Fatty acids are not dissolvable in water, ketone bodies can dissolve in water.

Question 9

In periods of extreme starvation, what substance other than glucose can the brain use for energy?

Answer 9

Ketone bodies

Question 10

Ketone bodies are a product of normal digestion in what type of animal?

Answer 10

Ruminants

Question 11

How does the liver use insulin?

Answer 11

To promote pathways to synthesize glucose

Question 12

How does glucose travel to the liver?

Answer 12

Portal vein

Question 13

How does the liver regulate blood glucose?

Answer 13

Takes up large portion of glucose and stores it as glycogen

Question 14

During glucose conversion to fatty acids, which molecule leaves the mitochondria to contribute to FA synthesis?

Answer 14

Citrate

Question 15

In the absorptive phase, storage or energy usage predominates?

Answer 15

Storage

Question 16

Which compound will allow glucose synthesis to proceed via gluconeogenesis?
A. Acetyl Co-A
B. Fatty acids
C. Oxaloacetate
D. Leucine

Answer 16

C

Question 17

In the liver, what is used to transport FA’s after they are synthesized?

Answer 17

Very-Low density lipoproteins

Question 18

What enzyme on endothelial cells of capillaries releases FA’s from chylomicrons and VLDLs?

Answer 18

Lipoprotein lipase

Question 19

Where else in the body is glucose taken up and converted to FAs?

Answer 19

Adipose tissue

Question 20

What two amino acids are removed by enterocytes before they can go to the portal vein?

Answer 20

Glutamate and aspartate

Question 21

Ketogenic amino acids can be converted into what?

Answer 21

Ketone bodies

Question 22

Glutamate is an analog of what other molecule?

Answer 22

Alpha-ketoglutarate

Question 23

Alanine is an analog of what other molecule?

Answer 23

Pyruvate

Question 24

What percentage of amino acids that reach the liver make it into general circulation?

Answer 24

23%

Question 25

The amino acids that enter carbohydrate metabolism can go in what three directions?

Answer 25

1. Metabolized for energy
2. Converted to glucose or glycogen
3. Shunted to fatty acid synthesis

Question 26

Where do true carnivores, with a natural diet, get their carbs from?

Answer 26

Glucogenic amino acids

Question 27

In ruminants, what volatile fatty acid is used to synthesize glucose?

Answer 27

Propionate

Question 28

The essential amino acids that are not removed by the liver go where?

Answer 28

Directly to periphery

Question 29

Where can non-essential amino acids be synthesized?

Answer 29

Protein producing tissues (muscle)

Question 30

What is the overall result of hepatic metabolism during the absorptive phase?

Answer 30

Removal of glucose and amino acids, and synthesis of protein and fatty acids

Question 31

T/F: the glycogen stored in muscle can be used anywhere in the body

Answer 31

False - it is only for muscle use