BIOL 111

Question 1

What do you call a monosaccharide with an aldehyde and what do you call one with a ketone

Answer 1

aldose and ketose

Question 2

What do you call a monosaccharide with 3 carbons

Answer 2

triose

Question 3

what side does the OH group sit on the D isomer

Answer 3

Right side

Question 4

What is the relationship between number of chiral atoms and optical isomers

Answer 4

2^n

Question 5

What does ketones and aldehydes reacting with hydroxyl groups mean for monosaccharides

Answer 5

It means they can form cyclic structures

Question 6

Where is the anomeric caron for ketones and where is it for aldehydes

Answer 6

C-2 for ketones and C-1 for aldehydes

Question 7

Name the two regions of a fatty acid

Answer 7

Carboxyl head group and hydrocarbon tail

Question 8

what is the difference between the two regions of a fatty acid

Answer 8

Tail is hydrophobic and head is hydrophillic so they are amphipathic (two different chem characteristics)

Question 9

What are the different suffixes for saturated, monounsaturated and polyunsaturated fatty acids

Answer 9

Saturated = anoic, monounsaturated = enoic
polyunsaturated = di/tri ect + enoic

Question 10

what prefixes do you use for unsaturated fatty acid naming

Answer 10

cis and trans (can be multiple e.g cis,cis,trans-9,12,14-octadeca…)

Question 11

Where do you start counting carbons on a fatty acid

Answer 11

at the carboxyl carbon

Question 12

Why can’t animals synthesise fatty acids beyond carbon 9

Answer 12

They do not have the desaturase enzyme

Question 13

what are essential fatty acids

Answer 13

unsaturated fatty acids that are needed but cannot be synthesised by animals

Question 14

What are good sources of essential fatty acids

Answer 14

fish oils (eat microalgae) and plant based spreads (e.g flora)

Question 15

What are the differences between neutral lipids and polar lipids

Answer 15

neutral lipids are energy stores whereas polar lipids have structural roles (e.g cell membranes)

Question 16

What is the important feature of triglycerides

Answer 16

It is an efficient energy store (more so than carbohydrates)

Question 17

Why do polyunsaturated fats have lower melting points

Answer 17

They can’t pack as tightly together and have more fluidity

Question 18

What differences in structure do cis and trans fats have

Answer 18

trans double bonds do not cause a bend like cis so they do not effect melting point and are implicated in circulatory diseases (naturally occuring fats are usually cis)

Question 19

how are phosphoglycerides composed

Answer 19

Two fatty acids attatched to a glycerol and a phosphate attatched to the other side of the glycerol with a variable group on the phosphate

Question 20

Why are membranes important

Answer 20

1) Seperate cell contents from surroundings
2) Maintain different envirnoments inside and outside membrane (organelles)
3) Selectively permeable

Question 21

How do phopspholipids move in the membrane

Answer 21

They move laterally rapidly (roughly 2um/s) but very rarely flip-flop their orientation

Question 22

What affects membrane fluidity

Answer 22

1) cholesterol acts as temperature buffer
2) more unsaturated fatty acids prevent packing increasing membrane fluidity and vice versa

Question 23

What affects protein movement in natural membranes

Answer 23

The cells actin cytoskeleton essentially fences the proteins in limiting their movement unless they rarely “hop” into another area

Question 24

What function do glycoproteins and glycolipids have

Answer 24

They act as tags for cell regognition (recognised by receptor proteins)

Question 25

What are some functions of membrane proteins

Answer 25

1) Membrane bound enzymes
2) Signal transduction (receptors)
3) intercellular joining
4) attachment to the cytoskeleton and extracellular matrix to maintiain cell shape

Question 26

How long is an oligosaccharide usually

Answer 26

shorter chains, longer chains are polysaccharides