Lecture 3.1: Macromolelecules 2

Question 1

What are carbohydrates?

Answer 1

-Carbon molecules with hydrogen groups and hydroxy groups
-They act as energy storage and transport molecules
-They also service carbon skeletons for other molecules

Question 2

What are monosaccharides?

Answer 2

they are monomers of carbohydrates; simple sugars

Question 3

What are disaccharides?

Answer 3

There are two monosaccharides linked by one covalent bond

Question 4

What are oligosaccharides?

Answer 4

They are carbohydrates that have between three and 20 monosaccharides

Question 5

What are polysaccharides?

Answer 5

We are carbohydrates composed of hundreds and hundreds of thousands of monosaccharides like starch, glycogen and cellulose

Question 6

What is the general formula for carbohydrate monomer?

Answer 6

it is Cn(H2O)n maintaining a ratio of one carbon to two hydrogen to one oxygen

Question 7

What happens to carbohydrates during polymerization?

Answer 7

It is a condensation reaction where water is removed, and therefore carbohydrate, polymers ratios differ somewhat from the 1:2:1 ratios of monomers.

Question 8

What are some isomers of monosaccharides?

Answer 8

Triose, Tetros, Pentoses and Hexoses

Question 9

What is the preferred energy source for cells?

Answer 9

Glucose

Question 10

In which shapes does glucose exist in? Which is the most stable one?

Answer 10

It can exist in straight chain or ring form. However, the ring form is the most stable one.

Question 11

What are the links between monosaccharides when they’re bounded together?

Answer 11

Glycosidic linkages. These can be an alpha or beta.

Question 12

How many glycosidic linkages do disaccharides have?

Answer 12

They only have one.

Question 13

Where are oligosaccharides usually found?

Answer 13

They are usually found covalently bonded to proteins and lipids.

Question 14

What are some examples of polysaccharides?

Answer 14

Starch, glycogen, and cellulose.

Question 15

Is fibre digestible for animals? If not, explain why.

Answer 15

No, fibre is not digestible for animals because they have the enzymes they can only hydrolyze alpha glycosidic links, but not the beta links.

Question 16

How can carbohydrates be modified?

Answer 16

By the addition of functional groups

Question 17

How are sugar phosphates created?

Answer 17

The are created when a phosphate is added to one or more hydroxy group

Question 18

How are amino sugars created?

Answer 18

They are created when amino groups can be substitute for alcohol groups.

Question 19

Are lipids soluble in water? Why not?

Answer 19

No, because the many non-polar covalent bonds of hydrogen and carbon in lipids, make them aggravate away from water, which is polar. Instead, they are attracted to each other via a weak, but additive, Vander walls forces.

Question 20

Which is the only group of macromolecules that does not consist of polymers?

Answer 20

Lipids

Question 21

What are lipids made up of then?

Answer 21

They are made up of smaller fatty molecules, such as “fatty” acids, and glycerol.

Question 22

What are fats and oils chemically?

Answer 22

They are triglycerides. They have three fatty acid moles, and one glycerol molecule.

Question 23

What is glycerol?

Answer 23

It is a three carbon molecule with three hydroxide groups.

Question 24

What are fatty acids?

Answer 24

They are long chains of hydrocarbons with a carboxyl group at one end.

Question 25

What are saturated fatty acids?

Answer 25

They have single carbon-to-carbon bonds, making them have rigid and straight structures. They are also solid at room temperature, which makes them fat.

Question 26

What are unsaturated fatty acids?

Answer 26

They have at least one double bonded carbon in one of the chains and their chains are not completely saturated with hydrogen atoms. Their double bonds causes “kinks” that prevent easy packing. Therefore, they are liquid at room temperature and are concerned to be oils.

Question 27

What are phospholipids?

Answer 27

They have two hydrophobic fatty acid tails and one hydrophilic phosphate, attach to the glycerol

Question 28

How do phospholipids orient themselves in aqueous solutions?

Answer 28

They create bilayers with their heads facing outward and their tails facing in words because they want their phosphate groups to face the water and their tail to face away from it.

Question 29

What makes phospholipids amphipathic ?

Answer 29

Because they have one hydrophilic end and one hydrophobic end.

Question 30

What are Cartenoids & Chlorophylls?

Answer 30

They are light absorbing pigments found mostly in plants.

Question 31

How is carotenoid-beta-carotene used in plants or animals?

Answer 31

In plants, it traps light for photosynthesis, and in animals, it can be broken into two molecules of vitamin A.

Question 32

What do steroids do?

Answer 32

They signal molecules and hormones.

Question 33

What are steroids made up of?

Answer 33

They consist of organic compounds with a series of fused rings.

Question 34

Which is a common steroid of the animal cell membrane and what is its main purpose in humans?

Answer 34

This main steroid is cholesterol, and it serves as an initial substrate for synthesis of the hormones, testosterone and estrogen.

Question 35

What are the fat soluble vitamins?

Answer 35

Vitamins A, D, E, and K

Question 36

Which vitamins are water soluble?

Answer 36

Vitamins B and C.

Question 37

What are waxes?

Answer 37

They are highly non-polar molecules, consisting of saturated, long fatty acids bonded to long fatty alcohols via and Esther linkage.

Question 38

What is the purpose of waxy coatings in nature?

Answer 38

In nature, they help repel water and prevent water loss from structures, such as hair for feathers and leaves.

Question 39

Which are the main two nucleic acids?

Answer 39

DNA and RNA.

Question 40

What are the monomer for nucleic acids called?

Answer 40

They are called nucleotides.

Question 41

What do nucleotides consist of?

Answer 41

A pentose sugar, a phosphate group and a nitrogen containing base.

Question 42

What is the backbone of DNA and RNA?

Answer 42

It is phosphate groups bonded by phosphodiester linkages.

Question 43

How many H-bonds can the A-T pair in DNA form?

Answer 43

2

Question 44

How many H-bonds can the G-C pair in DNA form?

Answer 44

5

Question 45

What are the bases for DNA?

Answer 45

They are adenine, cytosine, guanine, and thymine.

Question 46

True or False. The two strands of DNA run in the same direction.

Answer 46

False, they run in opposite directions. They are anti-parallel.

Question 47

The sequence of bases for DNA form a primary structure. However if two strands of DNA molecule come together, which structure do they form?

Answer 47

They form a secondary structure in the shape of a double helix.

Question 48

What are the four bases for RNA?

Answer 48

they are adenine, cytosine, guanine and uracil.

Question 49

What is the “replicator first” hypothesis?

Answer 49

It suggests that RNA must’ve come before DNA since DNA needs RNA to reproduce, but RNA can reproduce on its own.

Question 50

Where is the information stored for DNA?

Answer 50

it is stored in the order of the four different bases.

Question 51

Where does DNA send the order of their basis to next?

Answer 51

They send this order to RNA molecules, which then send the order to amino acids in proteins.

Question 52

Which is the other species that have the closest DNA similarity to humans?

Answer 52

chimpanzees