Chapter 4

Question 1

aer-

Answer 1

air. e.g., aerobic respiration: a respiratory process that requires oxygen.

Question 2

an-

Answer 2

without. e.g., anaerobic respiration: a respiratory process that does not require oxygen.

Question 3

ana-

Answer 3

up. e.g., anabolism: cellular processes in which smaller molecules are built up into larger ones.

Question 4

cata-

Answer 4

down. e.g., catabolism: cellular processes that break down larger molecules into smaller ones.

Question 5

co-

Answer 5

with. e.g., coenzyme: a substance that unites with a protein to complete the structure of an active enzyme molecule.

Question 6

de-

Answer 6

undoing. e.g., deamination: process that removes nitrogen-containing portions of amino acid molecules.

Question 7

mut-

Answer 7

change. e.g., mutation: change in genetic information.

Question 8

-strat

Answer 8

spread out. e.g., substrate: substance upon which an enzyme acts.

Question 9

sub-

Answer 9

under. e.g., substrate: a substance upon which an enzyme acts.

Question 10

-zym

Answer 10

causing to ferment. e.g., enzyme: a protein that speeds up a chemical reaction without itself being consumed.

Question 11

dehydration synthesis

Answer 11

is a type of anabolic process. For e.g., it builds up (joins) two monosaccharides to form a larger molecule: disaccharides. As it forms, one unit releases a hydroxyl group –OH, and another unit releases a hydrogen atom –H. These two react to produce a water molecule. The monosaccharides are joined by a shared oxygen atom as it becomes a disaccharide.

Question 12

Hydrolysis

Answer 12

is a type of catabolism process. It can decompose carbohydrates, lipids, and proteins. An, e.g., hydrolysis is the reverse of dehydration synthesis in which it breaks down the molecule. Take for, e.g., disaccharides. It uses a water molecule for each bond to break it down. It takes the disaccharides and separates them to yield two monosaccharides.

Question 13

Intermediary metabolism

Answer 13

refers to the processes that obtain, release, and use energy.

Question 14

Primary metabolites

Answer 14

are products of metabolism essential to survival.

Question 15

Secondary metabolites

Answer 15

are not essential to survival but may provide an advantage or enhancement. It is best studied in plants.

Question 16

Catalysis

Answer 16

is the accelerated chemical reaction rate. An enzyme is an organic catalyst.

Question 17

active site

Answer 17

is a region of the enzyme molecule that temporarily combines with a specific part of the substrate, forming an enzyme-substrate complex.

Question 18

State two factors that influence the rate of an enzyme-catalyzed reaction.

Answer 18

1. depends partly on the number of enzyme and substrate molecules in the cell. The reaction is faster if the concentration of the enzyme or the concentration of the substrate increases. 2. Some enzymes can catalyze only a few reactions per second, whereas others can catalyze hundreds of thousands.

Question 19

Metabolic pathways

Answer 19

lead to the synthesis or breakdown of particular biochemicals. Enzyme-catalyzed reactions form pathways when a reaction’s product is another’s substrate. It is a sequence of enzyme-controlled reactions.

Question 20

Rate-limiting enzyme

Answer 20

may regulate a metabolic pathway.

Question 21

Negative feedback

Answer 21

is a mechanism in which the product of a pathway inhibits the regulatory enzyme and may control the regulatory enzyme.

Question 22

Cofactor

Answer 22

it is the process of an inactive enzyme activating when it combines with a nonprotein component. They are additions to some enzymes that are necessary for their function. It may be an ion of an element such as copper, iron, or zinc, or a small organic molecule called a coenzyme.

Question 23

Coenzyme

Answer 23

is a substance that unites with a protein to complete the structure of an active enzyme molecule. Many coenzymes are composed of vitamin molecules or incorporate altered forms of vitamin molecules.

Question 24

Vitamins

Answer 24

are essential organic molecules that human cells cannot synthesize (or may not synthesize in sufficient amounts) and, therefore, must come from the diet.

Question 25

Energy

Answer 25

is the capacity to change something; it is the ability to do work. We recognize energy by what we can do. It cannot be created or destroyed, but it can change from one form to another. Common forms of energy are heat, light, sound, electrical energy, mechanical energy, and chemical energy.

Question 26

Cellular respiration

Answer 26

is the process that transfers energy from molecules such as glucose and makes it available for cellular use. It occurs in three distinct, yet interconnected series of reactions: glycolysis, the citric acid cycle, and the electron transport chain (oxidative phosphorylation)

Question 27

Adenosine triphosphate (ATP)

Answer 27

is a molecule that carries energy in a form the cell can use. It is the primary energy-carrying molecule in a cell. Cells quickly die without ATP. Each ATP molecule consists of three main parts: adenine, ribose, and three phosphates in a chain.

Question 28

Adenosine diphosphate (ADP)

Answer 28

is an Adenosine Triphosphate (ATP) molecule that lost its terminal (end) phosphate, which becomes two phosphates.

Question 29

Phosphorylation

Answer 29

is a process that uses energy released from cellular respiration to attach a third phosphate in order to convert ADP back to ATP.

Question 30

Oxidation

Answer 30

is a process that releases energy from glucose which is harnessed to power cellular metabolism.

Question 31

Glycolysis

Answer 31

the breaking of glucose. It occurs in the cytosol, and because it does not require oxygen, it is sometimes referred to as the anaerobic phase of cellular respiration. It is a series of ten enzyme-catalyzed reactions that break down the 6-carbon glucose molecule into two 3-carbon pyruvic acid molecules.

Question 32

Lactic acid

Answer 32

in anaerobic reactions, NADH and H+ donate electrons and hydrogens to pyruvic acid, thus generating lactic acid. Excess glucose in cells may be linked and stored as lactic acid.

Question 33

Deoxyribonucleic acid (DNA)

Answer 33

are molecules that contain and maintain information that tells a cell how to synthesize a particular protein. DNA molecule is a recipe book for protein. Its molecule is a double strand consisting of two poly-nucleotide chains.

Question 34

Genetic code

Answer 34

is the correspondence between a sequence of DNA nucleotides and a particular amino acid.

Question 35

Gene

Answer 35

is a DNA sequence that contains the information for making a particular polypeptide.

Question 36

Genome

Answer 36

is the complete set of genetic instructions in a cell, including the genes as well as other sequences.

Question 37

Exome

Answer 37

is only a small part of the human genome that encodes protein.

Question 38

Gene expression

Answer 38

The rest of the genome controls which proteins are produced in a particular cell under particular circumstances and the amounts produced.

Question 39

Nucleotides

Answer 39

are the building blocks of nucleic acids. It consists of a 5-carbon sugar (ribose or deoxyribose), a phosphate group, and one of several nitrogenous bases.

Question 40

Purines

Answer 40

are adenine and guanine (A, G). They consist of two organic ring structures. Purine will always bind to a pyrimidine. (T binds to A, and G binds to C).

Question 41

Pyrimidine

Answer 41

are thymine and cytosine (T, C). They consist of a single organic ring structure.

Question 42

Complementary base pairs

Answer 42

are the pair-bindings of A with T and G with C.

Question 43

DNA replication

Answer 43

is the process that creates an exact copy of a DNA molecule. It happens during interphase of the cell cycle. The double-stranded structure of the DNA molecule makes replication possible.