Biology Exam 2

Question 1

What are the monomers of proteins?

Answer 1

Amino Acids.

Question 2

What are the monomers of lipids?

Answer 2

Glycerol and fatty acids. (Polymer is triglyceride).

Question 3

What are the monomers of nucleic acids?

Answer 3

Nucleotides.

Question 4

What are the monomers of carbohydrates?

Answer 4

Monosaccharides.

Question 5

What is a functional group?

Answer 5

A functional group is a group of atoms linked by strong covalent bonds which tend to function in chemical reactions as a single unit.

Question 6

What are the functions of enzymes?

Answer 6

To catalyze chemical reactions in the body.

Question 7

What are the characteristics of enzymes?

Answer 7

a) Enzymes are substrate specific- “Lock and Key”. b) Enzymes contain “active sites”, where they bind with substrates. c) Enzymes are not destroyed by the reactions.

Question 8

Describe the four steps of an enzymatic reaction.

Answer 8

(a) Substrates approach active sites on enzyme. (b) Substrates bind to active sites, producing an enzyme–substrate complex. (c) Changes internal to the enzyme–substrate complex facilitate interaction of the substrates. (d) Products are released and the enzyme returns to its original form.

Question 9

Describe the four steps of an enzymatic reaction.

Answer 9

(a) Substrates approach active sites on enzyme. (b) Substrates bind to active sites, producing an enzyme–substrate complex. (c) Changes internal to the enzyme–substrate complex facilitate interaction of the substrates. (d) Products are released and the enzyme returns to its original form.

Question 10

What are the four levels of protein structure?

Answer 10

a) Primary structure -Sequence of amino acids joined by peptide bonds. b) Secondary structure - Alpha helix or beta sheet formed by hydrogen bonding. c) Tertiary structure - Folding and coiling due to further folding and bonding of the secondary structure. d) Quaternary structure - Association of two or more polypeptide chains with each other.

Question 11

What are saturated fatty acids?

Answer 11

Fatty acid chains that contain the maximum number of hydrogen atoms (no double carbon bonds).

Question 12

What are unsaturated fatty acids?

Answer 12

Fatty acids with one or more double carbon bonds.

Question 13

What are trans fatty acids?

Answer 13

Unsaturated fatty acids which have been chemically treated to produce partially hydrogenated fats.

Question 14

What is the reaction used to form ATP using glucose?

Answer 14

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP (Glucose + 6 Oxygen2 = 6 Carbon Dioxide + 6 Water + ATP).

Question 15

What are cilia?

Answer 15

Hair-like appendages found on certain cells. Cilia move mucus and its trapped particles up the airways out of the lungs.

Question 16

What are flagella?

Answer 16

An appendage specialized for cell locomotion. The only flagellated cell in humans is the sperm cell (its tail is a flagella).

Question 17

What are microvilli?

Answer 17

Stationary wave like extensions of the cell membrane that serve primarily to increase a cell’s surface area and are specialized for absorption.

Question 18

What are the functions of the phospholipid bilayer?

Answer 18

a) To maintain a barrier between the cell and its external environment b) To store and transport many of the proteins essential to the cell’s function.

Question 19

What is simple diffusion?

Answer 19

A mechanism of molecules moving across a cell membrane from the side where they are more concentrated to the side where they are less concentrated. (passive transport).

Question 20

What is facilitated diffusion?

Answer 20

A diffusion process used for those substances that cannot cross the lipid bilayer due to their size, charge and/or polarity. They are able to diffuse with the help of proteins in the cell membrane such as channel proteins and carrier proteins. (passive transport).

Question 21

What is osmosis?

Answer 21

The diffusion of water through a semipermeable membrane. (passive transport).

Question 22

What is active transport?

Answer 22

The transportation of a substance across a membrane (often against the concentration gradient), with the use of ATP.

Question 23

What is secondary active transport?

Answer 23

The passive transport of a substance which is powered by the action of an active transport.

Question 24

What is symport?

Answer 24

The facilitated diffusion of two or more substance in the same direction at the same time.

Question 25

What is antiport?

Answer 25

The facilitated diffusion of two or more substances in opposite directions across a cell membrane.

Question 26

How does a Na ATP pump function?

Answer 26

Powered by ATP, the pump moves sodium and potassium ions in opposite directions across a cell membrane, each against its concentration gradient. In a single cycle of the pump, three sodium ions are extruded from and two potassium ions are imported into the cell.

Question 27

What is endocytosis?

Answer 27

The process of a cell ingesting extra cellular material by enveloping it in a portion of its cell membrane (with material attached to its exterior) and then pinching off that portion of membrane.

Question 28

What is exocytosis?

Answer 28

The process of a cell exporting material by packaging it in a vesicular transport which fuses to the cell membrane and releases the content to extracellular space.

Question 29

What are the functions of membrane proteins?

Answer 29

a)To selectively allows particular materials, such as certain ions, to pass into or out of the cell. b) To serve to mark a cell’s identity so that it can be recognized by other cells.

Question 30

What is the function of cholesterol in the cell membrane?

Answer 30

To contribute to the fluidity of the membrane.

Question 31

What are the functions of carbohydrate chains in a cell membrane?

Answer 31

a) To aid in cell recognition. b) To form the glycoclayx which allows cells to bind together and may contain receptors for hormones.