Lecture 12 study guide

Question 1

List three biomolecules that can be processed and consumed as food.

Answer 1

carbohydrates, lipids, proteins

Question 2

What is the function of the nucleic acids? HINT: not a food source

Answer 2

store information used to make proteins

Question 3

State the free-energy change in (kcal) from the breakdown of glucose. How does that energy drive cellular work?

Answer 3

-686 kcal; the breakdown of glucose releases energy to power cellular work

Question 4

Oxidation vs Reduction

Answer 4

oxidation: electrons lost and hydrogens lost
reduction: electrons and hydrogens gained

Question 5

Why do oxidation and reduction ALWAYS occur together?

Answer 5

because the electrons and hydrogens are transferred during the reaction

Question 6

Describe the relationship between H, C and oxidation

Answer 6

the more H’s attached to the C, the more reduced the state; the less H’s (more O’s) attached to the see, the more oxidized (least reduced) state

Question 7

Briefly outline the relationship between electronegativity and the potential energy state of a chemical bond.

Answer 7

potential energy decreases as electronegativity increases

Question 8

Explain why organic molecules that contain a lot of C-H bonds serve as ‘high energy’ electrons donors.

Answer 8

it has low electronegativity

Question 9

The electron carrier (NAD+) serves as an oxidizing agent during respiration. The oxidation of organic molecules transfers a pair of hydrogen atoms to the electron carrier NAD+. NAD+ accepts 2 _____ and 1 _____

Answer 9

electrons; hydrogen

Question 10

In cellular respiration, glucose is oxidized to ____ and O2 is reduced to ___.

Answer 10

CO2; H2O

Question 11

Describe the role that NAD+ plays as an electron carrier in cellular respiration.

Answer 11

it is reduced to NADH by accepting two electrons and a hydrogen

Question 12

AH is __Glucose________ B is __________________A is __________________BH is _________________

Answer 12

AH is glucose, A is CO2; B is O2, BH is H2O

Question 13

Describe how ATP stores and releases energy.

Answer 13

energy is released when ATP is hydrolyzed to ADP + Pi

Question 14

List three cellular processes (also called cellular WORK) that use ATP as a source of energy.

Answer 14

transport work, mechanical work, chemical work

Question 15

Define phosphorylation.

Answer 15

the addition of a phosphate group

Question 16

How does phosphorylation differ from redox reactions?

Answer 16

phosphorylation is the addition of a phosphate group and Redox reaction are the transfer of electrons and hydrogen atoms in a reaction