metabolism

Question 1

What is metabolism?

Answer 1

The sum total of all chemical reactions that occur in a cell

Question 2

Define catabolic reactions.

Answer 2

Energy-releasing metabolic reactions

Question 3

Define anabolic reactions.

Answer 3

Energy-requiring metabolic reactions

Question 4

What is catabolism?

Answer 4

The breakdown of foodstuffs into smaller molecules, generating energy and building blocks

Question 5

What is anabolism?

Answer 5

The synthesis of many molecules that form the cell

Question 6

What percentage of a typical bacterial cell is carbon (by dry weight)?

Answer 6

~50%

Question 7

What type of carbon do heterotrophs use?

Answer 7

Organic carbon

Question 8

What type of carbon do autotrophs use?

Answer 8

Inorganic carbon

Question 9

What percentage of a typical bacterial cell is nitrogen (by dry weight)?

Answer 9

~12%

Question 10

List two macronutrients and their roles.

Answer 10

• Phosphorus (P): Synthesis of nucleic acids and phospholipids
• Sulfur (S): Sulfur-containing amino acids (cysteine and methionine)

Question 11

What are enzymes?

Answer 11

Biological catalysts that are typically proteins and highly specific

Question 12

What is the active site of an enzyme?

Answer 12

Region of enzyme that binds substrate

Question 13

What is the ‘lock and key’ model in relation to enzymes?

Answer 13

A model explaining how enzymes and substrates fit together

Question 14

What factors affect reaction velocity?

Answer 14

• Temperature
• pH
• Substrate concentration
• Enzyme concentration
• Products of the reaction
• Presence of activator/inhibitor
• Allosteric effects
• Time

Question 15

What is photosynthesis?

Answer 15

A process that converts electromagnetic energy in sunlight into chemical-bond energy in cells

Question 16

What is ATP?

Answer 16

Adenosine triphosphate, a molecule containing adenine, ribose, and three phosphate groups

Question 17

How is ATP synthesized?

Answer 17

By a condensation reaction catalyzed by ATP synthase

Question 18

What are NADH and NADPH?

Answer 18

Activated carriers of electrons specialized to carry high-energy electrons and hydrogen bonds

Question 19

What is the first stage of food molecule breakdown?

Answer 19

Catabolism, where enzymes convert large polymeric molecules into simpler monomeric subunits

Question 20

What are the phases of cellular respiration?

Answer 20

• Glycolysis
• Citric Acid Cycle
• Electron Transport Chain

Question 21

Where does glycolysis occur?

Answer 21

In the cytosol

Question 22

What is produced during glycolysis?

Answer 22

• 2 Pyruvate
• 2 ATP
• 2 NADH

Question 23

What is the Krebs Cycle?

Answer 23

A series of energy-extracting reactions where pyruvic acid is broken down into carbon dioxide

Question 24

What is the role of coenzyme A in the Krebs Cycle?

Answer 24

Joins the 2-carbon molecule to form acetyl-CoA

Question 25

What does the electron transport chain do?

Answer 25

Uses high-energy electrons to convert ADP into ATP

Question 26

What is the proton motive force?

Answer 26

The force generated by the movement of hydrogen ions across a membrane

Question 27

What is ATP synthase?

Answer 27

A complex that converts proton motive force into ATP

Question 28

How do photosynthesis and cellular respiration compare?

Answer 28

They involve energy flow in opposite directions