3.5: Physiology of the GI Tract Part II: Cell Metabolism

Question 1

______ is a set of chemical reactions that are essential for the body to sustain life.

Answer 1

Metabolism

Question 2

Metabolism is…….

Answer 2

Metabolism is a set of chemical reactions that are essential for the body to sustain life.

Question 3

______ is the set of reactions in which smaller molecules are combined to make larger, more complex molecules.

Answer 3

Anabolism

Question 4

Anabolism is……

Answer 4

Anabolism is the set of reactions in which smaller molecules are combined to make larger, more complex molecules.

Question 5

______ is the set of reactions in which larger molecules are broken down to be used as energy sources for the body.

Answer 5

Catabolism

Question 6

Catabolism is…….

Answer 6

Catabolism is the set of reactions in which larger molecules are broken down to be used as energy sources for the body.

Question 7

the ______ process is often used during growth and repair phases of the cell.

Answer 7

anabolic

Question 8

The most widely used form of energy in the cells is ______.

Answer 8

adenosine triphosphate or ATP

Question 9

If a phosphate group is removed from ATP it becomes ______.

Answer 9

adenosine diphosphate or ADP

Question 10

ATP has energy to___1___, while ADP can ___2___ energy (phosphate group) to become ATP.

Answer 10

1. donate
2. accept

Question 11

By donating available phosphate groups, ATP transfers energy from ___1___ reactions to be used for___2___.

Answer 11

1. catabolic (breaking down)
2. anabolism (building up)

Question 12

______ is defined as the process by which cells generate ATP.

Answer 12

Cellular respiration

Question 13

what is Cellular respiration?

Answer 13

Cellular respiration is defined as the process by which cells generate ATP.

Question 14

Most organisms carry out aerobic respiration, which requires ___1___ and releases ___2___,___3___, and ___4___.

Answer 14

1. oxygen and a fuel (glucose, for example)
2. carbon dioxide
3. water
4. ATP

Question 15

___1___ are the main source of energy for cells with the body digesting carbohydrates into ___2___.

Answer 15

1. Carbohydrates
2. glucose

Question 16

True or False: Glucose metabolism is used by the body primarily during high energy demands.

Answer 16

True

Question 17

True or False: As glucose is one of the most abundant biomolecules, the catabolism of glucose is an important metabolic pathway used by microorganisms for ATP production.

Answer 17

True

Question 18

What is the chemical make up of glucose?

Answer 18

C6H12O6

Question 19

The complete catabolism of a single molecule of glucose (C6H12O6) yields up to ______ ATP and involves three distinct transitions.

Answer 19

38

Question 20

What are the steps to glucose metabolizing?

Answer 20

1. glycolysis (2 ATP)
2. fermentation or respiration (2 ATP)
3. electron transport chain produces 34 ATP via an oxidative phosphorylation event at the plasma membrane.

Question 21

______ begins with the breakdown of a single molecule of glucose into two pyruvate molecules.

Answer 21

Glycolysis

Question 22

______ is an aerobic process (oxygen must be present) used by cells to produce energy.

Answer 22

Cellular respiration

Question 23

What is Cellular respiration?

Answer 23

Cellular respiration is an aerobic process (oxygen must be present) used by cells to produce energy.

Question 24

Respiration takes place inside and around the double membrane-enclosed organelle known as the ______.

Answer 24

mitochondria

Question 25

Fermentation, on the other hand, takes place in the absence of ______.

Answer 25

oxygen

Question 26

The central pathway of respiration is called the ______.

Answer 26

tricarboxylic acid (TCA) cycle, also known as the Krebs Cycle or the citric acid cycle.

Question 27

In the TCA cycle, the pyruvic acid (product of glycolysis) is converted to ______ forming some additional ATP.

Answer 27

carbon dioxide

Question 28

At its conclusion, the TCA cycle produces ___1___ ATP in total (one for each pyruvate processed) and an abundance of electron carriers, known as ___2___.

Answer 28

1. 2 2. NADH and FADH2

Question 29

What is the primary function of the TCA cycle?

Answer 29

The production of electron carriers, known as NADH and FADH2, as the transfer of these electrons will fuel the generation of ATP via the electron transport system.

Question 30

As electrons are transferred from NADH/FADH2 to ______, energy is released and captured by electron acceptor proteins located in the inner membrane of mitochondria.

Answer 30

terminal electron acceptors (O2; aerobic respiration)

Question 31

Electrons are then passed down a chain of electron acceptors (thus the name) causing ______to be pumped out of the membrane.

Answer 31

protons (H+; positive charge)

Question 32

The ___1___ drives H+ back through the ___2___, also located in the membrane, resulting in the production of up to ___3___ molecules of ATP.

Answer 32

1. proton motive force 2. ATP synthase complex 3. 34

Question 33

Under aerobic conditions (in the presence of oxygen), the complete catabolism of glucose yields ___1___ ATP from glycolysis, ___2___ ATP from the TCA cycle and ___3___ ATP from the electron transport system, for a total of ___4___ ATP from a single glucose molecule.

Answer 33

1. 2 2. 2 3. 34 4. 38

Question 34

______ occurs in the liver by a process known as beta-oxidation.

Answer 34

Lipid metabolism

Question 35

Lipid metabolism occurs in the ___1___ by a process known as ___2___.

Answer 35

1. liver 2. beta-oxidation

Question 36

Lipids are used by the body primarily during ______.

Answer 36

low energy activities

Question 37

True or False: Lipid metabolism yields half the amount of ATP than when a carbohydrate or protein is broken down.

Answer 37

False. Lipid metabolism yields TWICE the amount of ATP than when a carbohydrate or protein is broken down.

Question 38

A fat molecule is broken down in the mitochondria to form ______.

Answer 38

acetic acid

Question 39

Acetic acid is further catabolized by the TCA cycle to ___1___ forming some ___2___.

Answer 39

1. carbon dioxide 2. ATP molecules

Question 40

______ metabolism only takes place when carbohydrates and fats are unavailable to the body.

Answer 40

Protein

Question 41

Protein metabolism only takes place when___1___ and ___2___ are unavailable to the body.

Answer 41

1. carbohydrates 2. fats

Question 42

Proteins are the ______ for the cells and saved as a last resort.

Answer 42

1. building blocks

Question 43

When proteins must be used to form ATP, the ___1___ is removed from the protein to form ___2___.

Answer 43

1. amino group 2. ammonia

Question 44

True or False: Ammonia is harmful to the body and must be converted to a different form.

Answer 44

True

Question 45

Ammonia is combined with ___1___ in the liver to make ___2___.

Answer 45

1. carbon dioxide 2. urea

Question 46

Urea is then excreted from the body in ______.

Answer 46

urine

Question 47

Answer 47

Glycolysis is the process of breaking down a 6-carbon molecule of glucose into two 3-carbon molecules of pyruvate. This process yields 2 molecules of ATP per molecule of glucose.