The Structure and Function of Large Biological Molecules: Chp 5

Question 1

polymers

Answer 1

long chain molecules made of repeating subunits called monomers EX: starch is a polymer composed of glucose molecules. EX2: proteins are polymers composed of amino acid monomers

Question 2

dehydration reactions

Answer 2

create polymrs from monomers. two monomers are joined by removing one molecule of water

Question 3

hydrolysis

Answer 3

occurs when water is added to split large molecules. this occurs in the reverse of dehydration reaction

Question 4

carbohydrates

Answer 4

include both simple sugars (glucose, fructose, galactose) and polymers such as starch made from these and other subunits. . All carbohydrates exist in a ratio of 1 carbon: 2 hydrogen: 1 oxygen

Question 5

monosaccharides

Answer 5

the monomers of carbohydrates. EX: glucose and ribose

Question 6

polysaccharides

Answer 6

polymers of monosaccharides EX: starch, cellulose, and glycogen

Question 7

functions of polysaccharides

Answer 7

energy storage and structural support

Question 8

energy-storage polysaccharides

Answer 8

• starch is a storage polysaccharide found in plants

- glycogen is a storage polysaccharide found in animals, vertebrate muscle cells, and liver cells

Question 9

structural-support polysaccharides

Answer 9

• cellulose is a majorcomponent of plant cell walls
• chitin is found in the exoskeleton of arthropods, such as lobsters and insects and the cell walls of fungi. It gives cockroaches their “crunch”

Question 10

what type of molecules are lipids

Answer 10

they are hydrophobic. they are also NOT polyermes because they are assembled from a variety of components

Question 11

what are fats made up of

Answer 11

a glycerol molecule and three fatty acid molecules

Question 12

what are fatty acids composed of

Answer 12

hydrocarbon chains of variable lengths. the chains are nonpolar and therefore hydrophobic

Question 13

characteristics of saturated fatty acids

Answer 13

-have no double bonds between carbons
-tend to pack solidly at room temperature
-are linked to cardiovascular disease
-are commonly produced by animals
EX: butter and lard

Question 14

characteristics of unsaturated fatty acids

Answer 14

-have some carbond double bond that results in kinks
-tend to be liquid at room temperature
-commonly produced by plants
EX: corn oil and olive oil

Question 15

functions of lipids

Answer 15

• energy storage (fats store twice as many calories/grams as carbs)
• protection of vital orans and insulation

Question 16

characteristics of phospholipids

Answer 16

• have a glycerol backbond (head), which is hydrophilic
• have two fatty acid tails, which are hydrophobic
• are arranged in a bilayer in forming the cell membrane, with the hydrophilic heads pointing toward the watery cytosol of extracellular environment, and hydrophobic tails sandwiched in between

Question 17

steroids

Answer 17

made up of four rings that are fused together

Question 18

cholesterol

Answer 18

a steroid. It is a common component of cell membranes

Question 19

estrogen

Answer 19

steroid hormone

Question 20

testosterone

Answer 20

steroid hormone

Question 21

proteins

Answer 21

polymers made up of amino acid monomers

Question 22

amino acids

Answer 22

contain a central carbon bonded to a carboxyl group, an amino group, a hydrogen atom, and an R group

Question 23

peptide bonds

Answer 23

link amino acids. formed by dehydration synthesis

Question 24

four levels of protein structure

Answer 24

primary structure is the unique sequence in which amino acids are joined. Secondary structure refers to one of two three-dimensional shapes that are the result of hydrogen bonding. Alpha helix are coiled shapes that appear like a slinky. Beta pleated sheets are accordion shaped. Tertiary structure results in a complex globular shape, due to interactions between R groups, such as hydrophobic interactions, van der waals interactions, hydrogen bonds, and disulfide bridges. globular proteins such as enzymes are held in position by the R group interactions. Quaternary structure refers to the association of two or more poly peptide chains into one large protein. Hemoglobin is a globular protein with quaternary structure, as it is composed of four chains.

Question 25

why is protein shape crucial to protein function

Answer 25

when a protein does not fold properly, its function is changed. This can be the result of a single amino acid substitution, such as that seen in the abnormal hemoglobin typical of sickle-cell disease

Question 26

chaperonins

Answer 26

protein molecules that assist in the proper folding of proteins within cells. they provide an isolating environment in which a polypeptide chain may attain final conformation

Question 27

what does it mean when a protein is denatured

Answer 27

when a protein is denatured it loses its shape and ability to function due to heat, a change in pH, or some other disturbance

Question 28

nucleic acids

Answer 28

DNA and RNA (their monomers are nucleotides)

Question 29

what are nucleotides made up of

Answer 29

nitrogenous base, pentose, and phosphate group

Question 30

characteristics of DNA

Answer 30

• double-stranded helix
• its nucleotides are adenine, thymine, cytosine, and guanine
• adenine nucleotides will hydrogen bond to thymine nucleotides, and cytosine to guane

Question 31

characteristics of RNA

Answer 31

• single stranded

- nucleotides are adenine, uracil, cytosine, and guanine