Exam 2

Question 1

___ is a product of glycolysis, pyruvate processing, and the citric acid cycle

Answer 1

NADH

Question 2

What is a cofactor?

Answer 2

an inorganic ion that reversibly interacts with an enzyme

Question 3

Suppose you discovered a new amino acid. Its R-group contains only hydrogen and carbon atoms. Predict the behavior of its amino acid

Answer 3

It is hydrophobic

Question 4

The tertiary structure of a protein is the ___.

Answer 4

unique three-dimensional shape of the fully folded polypeptide

Question 5

A cell with a predominance of free ribosomes is most likely ____.

Answer 5

primarily producing proteins in the cytosol

Question 6

If a solution surrounding a cell is hypertonic relative to the inside of a cell, how will water move?

Answer 6

It net movement of water will be out of cell via osmosis

Question 7

What determines the secondary structure of a DNA molecule?

Answer 7

Hydrophobic interactions and hydrogen bonding

Question 8

Where does the citric acid cycle occur in eukaryotes?

Answer 8

in the matrix of mitochondria

Question 9

What contains hydrolytic enzymes?

Answer 9

Lysosome

Question 10

The bonding of two amino acid molecules to form a larger molecule requires the ____

Answer 10

release of a water molecule

Question 11

Steroids are considered to be lipids because they ____

Answer 11

are not soluble in water

Question 12

As cells grow larger, there is a detriment to efficient function. How do eukaryotic cells overcome the ineffieciency?

Answer 12

Eukaryotic cells have organelles in the cytosol, which decreases the overall cytosolic fluid volume, allowing less room for reactions and thus increasing efficiency

Question 13

What is the difference between a ribonucleotide and a deoxyribonucleotide?

Answer 13

Ribonucleotides have a hydroxyl group on the 2 carbon of their sugar subunit

Question 14

What statement is true about NAD+?

Answer 14

NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle

Question 15

What type of bond is directly involved in the formation of an alpha-helix?

Answer 15

Hydrogen bonds between amino acid residues

Question 16

How do the alpha and beta forms of glucose differ?

Answer 16

Their ring structures differ in the location of a hydroxyl group

Question 17

The evolution of eukaryotic cells most likely involved ____

Answer 17

endosymbiosis of an aerobic bacterium in a larger host cell-the endosymbiont evolved into mitochondria

Question 18

In glycolysis, for each molecule of glucose oxidized to pyruvate

Answer 18

two molecules of ATP are used and four molecules of ATP are produced

Question 19

One of the primary functions of RNA molecules is to ____

Answer 19

function in the synthesis of proteins

Question 20

A glycosidic linkage is analogous to which of the following in proteins?

Answer 20

a peptide bond

Question 21

Which plant cell organelle contains its own DNA and ribosomes?

Answer 21

mitochondrion

Question 22

Starting with one molecule of glucose, the energy-containing products of glycolysis are ____

Answer 22

2 NADH, 2 pyruvate, and 2 ATP

Question 23

What component of amino acid structure varies among different amino acids?

Answer 23

the components of the R-group

Question 24

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

Answer 24

It is lost to the environment

Question 25

The ____ functional group can always be found in a carbohydrate molecule

Answer 25

hydroxyl

Question 26

What can you infer about a high-molecular-weight protein that cannot be transported into the nucleus?

Answer 26

It lacks a nuclear localization signal (NLS)

Question 27

How does the structure of DNA allow it to be copied?

Answer 27

After separating the strands of a DNA double helix, each template strand can be copied to make two identical DNA molecules

Question 28

Nucleic acids are polymers made up of which of the following monomers?

Answer 28

Nucleotides

Question 29

What are polysaccharides?

Answer 29

Cellulose, Glycogen, amylopectin, and chitin

Question 30

Most hydrophilic

Answer 30

Electrically charged side chains

Question 31

Most hydrophobic

Answer 31

Nonpolar side chains

Question 32

Present in a prokaryotic cell

Answer 32

Ribosome

Question 33

Glycolysis is a series of ___ reactions that occurs in the ____ of the cells

Answer 33

10; cytoplasm

Question 34

What are the four nitrogenous base found in RNA?

Answer 34

Adenine, Cytosine, Guanine, Uracil (A, C, G, U)

Question 35

Which are a needed component of each monomer to make proteins?

Answer 35

Carboxyl group (COOH), amino functional group (NH2), and a side chain (R)

Question 36

What are three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria?

Answer 36

They have their own small, often circular chromosomes, they produce their own ribosomes, and they replicate independently of cellular division

Question 37

Which type of interaction stabilizes the alpha helix and the beta pleated sheet structures of proteins?

Answer 37

hydrogen bonds

Question 38

Glycolysis is active when cellular energy levels are ____ the regulatory enzyme, phosphofructokinase, is ____ by ATP

Answer 38

low; inhibited

Question 39

What are three ways monosaccharides differ from one another?

Answer 39

The orientations of their hydroxyl groups, the number of carbon atoms they contain, and the location of their carbonyl groupd

Question 40

If you wanted to radioactively label the nucleic acids separately from the protein, you would use radioactive ____

Answer 40

phosphorus

Question 41

Describe a reason why fats store more energy than carbohydrates

Answer 41

compared to carbohydrates , fatty acid chains have a higher ration of bonds with high potential energy to bonds with low potential energy

Question 42

How do the secondary structures of DNA and RNA differ?

Answer 42

DNA consists of two nucleotide strands, and RNA consists of one that often folds on itself

Question 43

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is in the form of ________.

Answer 43

NADH

Question 44

Which structure is the site of the synthesis of proteins that may be exported from the cell?

Answer 44

rough ER

Question 45

Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read?

Answer 45

They bind to receptor proteins

Question 46

Redox reactions involve the gain or loss of

Answer 46

electrons

Question 47

Lipids ____

Answer 47

are insoluble in water

Question 48

Why is ATP an important molecule in metabolism?

Answer 48

It energetically couples exergonic and endergonic reactions

Question 49

Under what circumstances does membrane transport require energy?

Answer 49

whenever a solute is moved against its electrochemical gradient

Question 50

The glucose molecule has a large quantity of energy in its ____

Answer 50

C-H bonds

Question 51

Lipids are insoluble in water because ____

Answer 51

they contain nonpolar C-C and C-H bonds

Question 52

Which involves an increase in entropy?

Answer 52

hydrolysis

Question 53

Which bonds are created during the formation of the primary structure of a protein?

Answer 53

peptide bonds

Question 54

What produces and modifies polysaccharides that will be secreted?

Answer 54

Golgi apparatus

Question 55

Which aspect of phospholipids is most important to the formation of bilayers?

Answer 55

they are amphipathic

Question 56

What two functional groups are bound to the central carbon of every free amino acid monomer?

Answer 56

An amino group and a carboxyl group