Lab 3: Chemical Composition of Cells

Question 1

Atoms

Answer 1

basic units of matter, that all organisms consist of

Question 2

Biomolecules

Answer 2

proteins, carbohydrates, and lipids

Question 3

How are macromolecules (biomolecules) formed?

Answer 3

they form during dehydration reactions when smaller molecules bond as water is given off

Question 4

Hydrolysis reaction

Answer 4

bonds are broken when water is added

Question 5

A fat (lipid) contains:

Answer 5

one glycerol and three fatty acids

Question 6

Monomers

Answer 6

smaller molecules

Question 7

Polymers

Answer 7

made up of multiple monomers

Question 8

What is the monomer in proteins?

Answer 8

amino acids

Question 9

How are the amino acids bonded?

Answer 9

by a peptide bond

Question 10

Monosaccharides in a polysaccharide (carbohydrates)

Answer 10

glucose molecules

Question 11

Positive control

Answer 11

color change

Question 12

Negative control

Answer 12

no color change

Question 13

What benefit is a positive control?

Answer 13

positive controls give you a standard by which to tell if the substance being tested is present (or acting properly) in an unknown sample

Question 14

What benefit is a negative control?

Answer 14

negative controls ensure that the experiment is giving reliable results

Question 15

Enzyme

Answer 15

proteins that speed chemical reactions, ex. amaylse

Question 16

All amino acids differ by:

Answer 16

the R group (remainder group) attached to a carbon atom

Question 17

Peptide

Answer 17

a chain of two or more amino acids

Question 18

Polypeptide

Answer 18

a very long chain of amino acids

Question 19

Dipeptide

Answer 19

the bonding of two amino acids through a dehydration reaction

Question 20

Biuret reagent tests for:

Answer 20

proteins (purple) and peptides (pinkish-purple)

Question 21

Biuret reagent contains:

Answer 21

a strong solution of sodium or potassium hydroxide (NaOH or KOH) and a small amount of dilute copper sulfate (CuSO4) solution

Question 22

Enzymes are composed of what type of organic molecules?

Answer 22

proteins

Question 23

Is starch a protein?

Answer 23

no

Question 24

What are carbohydrates?

Answer 24

sugars and molecules that are chains of sugars

Question 25

What is the monosaccharide in carboyhdrates?

Answer 25

glucose, contains one sugar unit

Question 26

What is the disaccharide in carbohydrates?

Answer 26

maltose, which has two sugar units

Question 27

Polysaccharides of carbohydrates:

Answer 27

glycogen, starch, and cellulose

Question 28

Animals store glucose as:

Answer 28

glycogen

Question 29

Plants store glucose as:

Answer 29

starch

Question 30

Starch consists of:

Answer 30

amylose that is nonbranched and amylopectin that is branched

Question 31

Iodine tests for:

Answer 31

starch

Question 32

If a solution is positive for starch it turns:

Answer 32

blue/black

Question 33

If a solution is negative for starch it turns:

Answer 33

brown

Question 34

What stores glucose as starch? Potatoes or onions?

Answer 34

potatoes

Question 35

Benedict's reagent tests for:

Answer 35

sugar molecules

Question 36

If a solution is positive for sugar it turns:

Answer 36

green (very low), yellow (low), yellow-orange (moderate), orange (high), orange-red (very high)

Question 37

If a solution if negative for sugar it turns:

Answer 37

blue

Question 38

What are lipids soluble and insoluble in?

Answer 38

lipids are insoluble in water and soluble in solvents, such as alcohol and ether

Question 39

Lipids includes:

Answer 39

fats, oils, phospholipids, steroids, and cholesterol

Question 40

Oils and fats are composed of:

Answer 40

three molecules of fatty acids bonded to one molecule of glycerol

Question 41

Phospholipids are composed of:

Answer 41

two molecules of fatty acids bonded to one molecule of glycerol and one phosphate group

Question 42

What are steroids derived from?

Answer 42

cholesterol

Question 42

Steroids and cholesterol are composed of:

Answer 42

skeletons of four fused rings of carbon atoms, but they differ by functional groups (attached side chains)

Question 43

Brown paper tests for:

Answer 43

fats and oils

Question 44

If a solution if positive for fats it turns:

Answer 44

translucent

Question 45

If a solutions is negative for fats it turns:

Answer 45

solid

Question 46

What kind of protein if lactase, the biomolecule that speeds up the breakdown of lactose?

Answer 46

enzyme

Question 47

What is another name for plant fats?

Answer 47

oils

Question 48

What must be present to successfully break down fats during digestion?

Answer 48

emulsifier