unit 3

Question 1

how do carbon atoms share their electron?

Answer 1

through covalent bonding

Question 2

what is covalent bonding?

Answer 2

Chemical bond in which two atoms share electrons, thereby completing their valence shells

Question 3

carbons tend to form with other carbon atoms forming a…

Answer 3

carbon skeleton. can form more than one covalent bond with one another; double and triple bonds are possible

Question 4

hydrocarbons:

Answer 4

in organic compounds, H atoms and C atoms link together

Question 5

functional group

Answer 5

group of atoms linked by strong covalent bonds and tending to function in chemical reactions as a single unit. You can think of functional groups as tightly knit “cliques” whose members are unlikely to be parted.

Question 6

5 functional groups

Answer 6

hydroxyl, carboxyl, amino, methyl and phosphate groups

Question 7

hydroxyl group

Answer 7

OH- polar group. involved in dehydration synthesis and hydrolysis reactions and H bonding

Question 8

carboxyl group

Answer 8

COOH- component of organic acids

Question 9

amino

Answer 9

NH2- component of all amino acids

Question 10

methyl

Answer 10

CH3- component of all fatty acids

Question 11

Phospholipids

Answer 11

PO4^2- : component of all phospholipids and nucleotides

Question 12

how does carbon bonding help make macromolecules?

Answer 12

Carbon’s ability to form covalent bonds allows many stable organic molecules to easily combine into larger, more complex ones.

Question 13

how do monomers form polymers

Answer 13

• some macromolecules are made up of several “copies” of single units called monomer (mono- = “one”; -mer = “part”). Like beads in a long necklace, these monomers link by covalent bonds to form long polymers (poly- = “many”). There are many examples of monomers and polymers among the organic compounds.
• monomers form polymers by dehydration synthesis

Question 14

how do polymers split to monomers

Answer 14

by hydrolysis: water breaks the bond. hydroxyl is given to one atom and H is given to the other

Question 15

chemical formula for carbohydrate:

Answer 15

(CH2O)n

Question 16

what does a carbohydrate contain?

Answer 16

composed of carbon, hydrogen, and oxygen; in most carbohydrates, hydrogen and oxygen are found in the same two-to-one relative proportions they have in water

Question 17

carbs are also referred to as….

Answer 17

saccharides- “sugar”

Question 18

carbs have 3 types:

Answer 18

• monosaccharide- monomers of carbs
• disaccharides: made up of 2 monomers
• polysaccharides: the polymers. can consist of hundreds to thousands of monomers

Question 19

5 important monosaccharides in the body:

Answer 19

(hexose- 6 carbons)
1. glucose
2. fructose
3. galactose

(pentose- 5 carbons)
4. ribose
5. deoxyribose

Question 20

disaccharide is a…

Answer 20

pair of monosaccharides. make via dehydration synthesis. linked by a glycosidic bond.

Question 21

3 disaccharide important to humans

Answer 21

• sucrose
• lactose
• maltose

Question 22

what forms sucrose?

Answer 22

monosaccharides glucose and fructose bond to form sucrose

Question 23

what forms lactose?

Answer 23

galactose and glucose

Question 24

maltose?

Answer 24

two glucose molecules

Question 25

starches are polymers of glucose- how do they occur

Answer 25

They occur in long chains called amylose or branched chains called amylopectin, both of which are stored in plant-based foods and are relatively easy to digest.

Question 26

starches are....

Answer 26

polymers of glucose

Question 27

glycogen is a

Answer 27

polymer of glucose

Question 28

how is glycogen stored?

Answer 28

stored in the tissues of animals, especially in the muscles and liver. It is not considered a dietary carbohydrate because very little glycogen remains in animal tissues after slaughter; however, the human body stores excess glucose as glycogen, again, in the muscles and liver.

Question 29

cellulose is a

Answer 29

polysaccharide made of glucose. Cellulose, a polysaccharide made of glucose that is the primary component of the cell wall of green plants, is the component of plant food referred to as “fibre”. In humans, cellulose/fibre is not digestible; however, dietary fibre has many health benefits. It helps you feel full so you eat less, it promotes a healthy digestive tract, and a diet high in fibre is thought to reduce the risk of heart disease and possibly some forms of cancer.

Question 30

body obtains carbs from

Answer 30

-plant-based foods. -Grains, fruits, and legumes and other vegetables provide most of the carbohydrates in the human diet, although lactose is found in dairy products.

Question 31

glucose stored in the body as:

Answer 31

glycogen

Question 32

pentose sugars are important because:

Answer 32

critical structures of ATP, and the nucleotides make up DNA and RNA

Question 33

lipid is a

Answer 33

Highly diverse group of compounds make mostly out of hydrocarbons

Question 34

why are lipids hydrophobic?

Answer 34

due to non polar hydrocarbons

Question 35

in water lipids form an

Answer 35

emulsion- not mixing well

Question 36

triglyceride is a compound formed of covalent bonds between:

Answer 36

3 fatty acids and one glycerol backbone

Question 37

what is a glycerol

Answer 37

contains three carbon atoms, each bonded to a hydroxyl group.

Question 38

what does a fatty acid consist of

Answer 38

long chains of hydrocarbons with a carboxyl group and a methyl group at opposite ends, extend from each of the carbons of the glycerol. These hydrocarbon chains are formed with nonpolar bonds, making them hydrophobic in terms of chemical nature.

Question 39

how do triglycerides form?

Answer 39

dehydration synthesis- 3 water molecules are produced - glycerol gives up H atom at each carboxyl group at every bond - and the carboxyl group on each fatty acid chain gives up a hydroxyl group

Question 40

what makes a fatty acid saturated?

Answer 40

fatty acid chains have no double Carbon bonds because they have the maximum amount of H atoms which makes them saturated fatty acids. unsaturated fatty acids will have a double carbon bond, and are KINKED RATHER THAN STRAGIHT

Question 41

how do triglycerides impact the human body?

Answer 41

are a major fuel source for the body and are used when glucose storages are low or during extended fasting conditions. Triglycerides also fuel long, slow physical activity such as gardening or hiking, and contribute a modest percentage of energy for vigorous physical activity

Question 42

a phospholipid is formed by

Answer 42

glycerol component of a lipid and phosphorous molecule

Question 43

a phospholipid contains

Answer 43

derived from diglyceride- glycerol backbone with two fatty acids and a phosphorus containing group (polar head)

Question 44

triglycerides are

Answer 44

hypdrophobic

Question 45

phospholipids are

Answer 45

- hydrophilic because of the polar charge on the phosphorus head - phospholipids are said to have hydrophobic tails, containing the neutral fatty acids, and hydrophilic heads, containing the charged phosphate groups and nitrogen atom.

Question 46

a steroid compound is made up of

Answer 46

hydrocarbons rings bonded to other atoms/molecules

Question 47

what is the most important sterol for humans?

Answer 47

cholesterol

Question 48

cholesterol is...

Answer 48

hydrophobic due to hydrocarbons, but has a hydrophilic polar hydroxyl head.

Question 49

what does cholesterol do for hormones?

Answer 49

building block for hormones

Question 50

what is a protein?

Answer 50

organic molecule composed of amino acids linked together by peptide bonds

Question 51

protein includes:

Answer 51

- Keratin in skin (protects underlying tissues) - Collagen in skin (dermis), bones, and meninges (brain/spinal cord)

Question 52

functional roles of proteins:

Answer 52

-Digestive enzymes (digestive tract) -Antibodies -Neurotransmitters (neuron communication) -Peptide-based hormones (e.g., growth hormone)

Question 53

composition of proteins:

Answer 53

Contain nitrogen (N), sulfur (S), carbon (C), hydrogen (H), oxygen (O) Varying ratios depending on structure.

Question 54

amino acids are composed of

Answer 54

-a hydrogen atom -an alkaline (basic) amino group NH2 (see Table 1) -an acidic carboxyl group COOH (see Table 1) -a variable group

Question 55

how do protein polymers form?

Answer 55

via dehydration synthesis of monomers- amino acids. join by forming peptide bonds (covalent bond between two amino acids)

Question 56

shapes of proteinds

Answer 56

(a) The primary structure is the sequence of amino acids that make up the polypeptide chain. (b) The secondary structure, which can take the form of an alpha-helix or a beta-pleated sheet, is maintained by hydrogen bonds between amino acids in different regions of the original polypeptide strand. (c) The tertiary structure occurs as a result of further folding and bonding of the secondary structure. (d) The quaternary structure occurs as a result of interactions between two or more tertiary subunits. The example shown here is hemoglobin, a protein in red blood cells which transports oxygen to body tissues

Question 57

functions of protein:

Answer 57

- movement - mechanical transport - catalytic action - transport specific molecules - regulate body fluid pH - regulate metabolism - defend the body - The body can use proteins for energy when carbohydrate and fat intake is inadequate

Question 58

nucleotides contain:

Answer 58

one or more phosphate groups a pentose sugar: either deoxyribose or ribose a nitrogen-containing base: adenine, cytosine, guanine, thymine, or uracil

Question 59

nucleotides can be turned into:

Answer 59

nucleic acids (DNA or RNA) or the energy compound adenosine triphosphate.

Question 60

ATP is composed of:

Answer 60

a ribose sugar, an adenine base, and three phosphate groups

Question 61

ATP is considered high energy because:

Answer 61

two covalent bonds linking phosphate groups contains a high amount of potential energy

Question 62

energy released from covalent bonds in ATP helps:

Answer 62

fuel the body’s activities, from muscle contraction to the transport of substances in and out of cells to anabolic chemical reactions.

Question 63

how is adenosine diphosphate produced? what about adenosine monophosphate?

Answer 63

phosphate group cleaved from ATP hydrolysis rxn: ATP + H2O → ADP + Pi (inorganic phosphate) + energy AMP- another phosphate group removed They are reversible, too, as when ADP undergoes phosphorylation. Phosphorylation is the addition of a phosphate group to an organic compound, in this case, resulting in ATP.

Question 64

what is in DNA?

Answer 64

- DNA contains deoxyribose plus one phosphate group and one nitrogen-containing base. - The bases for DNA can be adenine, cytosine, guanine, and thymine.

Question 65

what is in RNA?

Answer 65

RNA contains ribose, one phosphate group, and one nitrogen-containing base, but the bases for RNA are one of adenine, cytosine, guanine, and uracil.