Physiology: Digestion, Absorption & Metabolism of Carbohydrates, Lipids & Proteins- Student Objectives (not done)

Question 0

List the basic components of a simple homeostatic control system. (3)

Answer 0

1. sensor
2. method to conduct and transmit the electrical/chemical message
3. effector

Question 1

Define homeostasis.

Answer 1

The ability of organisms to maintain their internal environment regardless of changes to the external environment.

Question 2

Explain why organisms must expend energy continuously.

Answer 2

Because exerting homeostatic control requires energy.

Question 3

List molecular sources of energy used by animals.

Answer 3

1. glucose
2. volatile fatty acid
3. fatty acids
4. amino acids
   (5. ketones)

Question 4

What is a biochemical pathway?

Answer 4

A sequence of chemical reactions allowing for orderly transformation from one molecule to another that allows for utilization of the sources of energy.

Question 5

List the biochemical pathways which are utilized to obtain energy from carbohydrate, lipid, and protein.

Answer 5

Glycolysis
Krebs cycle
Beta-oxidation 
Deamination and transamination 
(Gluconeogenesis)

Question 6

What is glycolysis?

Answer 6

Process by which glucose is oxidized in the absence of oxygen and then converted into 2 pyruvate molecules and the only way anaerobic cells can generate ATP.

Question 7

What is the Krebs Cycle (Citric Acid, TCA)?

Answer 7

A process by which acetyl CoA molecule derived from pyruvate, volatile fatty acids and amino acids are condensed with oxaloacetate to form citrate molecules that are then oxidized in the presence of oxygen.

Question 8

What is Beta-Oxidation?

Answer 8

A process by which fatty acids are converted to acetyl-CoA molecules in the mitochondria. Also produces reduced cofactors which are oxidized in the ETC in the presence of oxygen.

Question 9

What is deamination & transamination?

Answer 9

A process by which an amine group is removed from amino acids producing acetyl CoA molecules or molecular intermediates of the TCA cycle which can be oxidized in the presence of O2.

Question 10

What is gluconeogenesis?

Answer 10

A pathway by which non-carbohydrate precursors are converted into glucose.

Question 11

Define anabolism.

Answer 11

The manufacture of large & complex molecules/structures which is powered by catabolism.

Question 12

Define catabolism.

Answer 12

The breakdown of large molecules into smaller ones that releases the energy required to perform the work of anabolic reactions.

Question 13

Define metabolism.

Answer 13

The sum of all anabolic and catabolic reactions in an organism and the reactions involved in the disposal of waste products of anabolic and catabolic reactions.

Question 14

Define digestion.

Answer 14

.

Question 15

Define absorption.

Answer 15

A process involved in the transport of molecules from the lumen of the GI tract through the epithelium of the GI tract and eventually into the bloodstream.

Question 16

Define oxidation.

Answer 16

A loss of electrons accompanied by the release of energy.

Question 17

Define reduction.

Answer 17

A gain of electrons.

Question 18

Define fermentation.

Answer 18

Oxygen absent or in short supply causes an organic molecule to serve as the ultimate electron acceptor–only occurs in carbohydrates and only through the glycolytic pathway.

Question 19

Define aerobic respiration.

Answer 19

Oxidation in the presence of oxygen occurring in all cells which have mitochondria (O2 is reduced in mitochondria).

Question 20

Define anaerobic respiration.

Answer 20

Performed in the cytoplasm by cells lacking O2 or mitochondria.

Question 21

Explain the importance of glycolysis under anaerobic conditions.

Answer 21

.

Question 22

Explain the significance of elevated plasma lactate.

Answer 22

Increased anaerobic process (glycolysis).

Increased lack of oxygen.

Question 23

State the major form in which carbohydrate is ingested by animals.

Answer 23

.

Question 24

List the different carbohydrate molecules ingested by animals and state whether they are found in plants, animals, or both.

Answer 24

.

Question 25

Describe the basic molecular difference between carbohydrate polymers that are utilized for energy storage and those that are utilized for structural purposes.

Answer 25

.