carbohydrates, fatty acids and lipids

Question 1

what are the roles of carbohydrates?

Answer 1

they coat cell surfaces
they’re used for the modification of secreted proteins to protect them from degradation
they form part of receptors for lots of pathogens
they form the basic blood groups

Question 2

what are carbohydrates made from?

Answer 2

monosaccharides linked by glycosidic linkages

Question 3

what do the names of all the sugars end in?

Answer 3

-ose

Question 4

what type of molecules are monosaccharides?

Answer 4

aldehydes and ketones

Question 5

what are the basic names of the monosacharides?

Answer 5

3C monosaccharides- triose
4C monosaccharides= tetraoses
5C monosaccharides = pentoses
6C monosaccharides = hexoses
7C monosaccharises= heptoses

Question 6

what form is glucose mostly in?

Answer 6

the ring form as its more energetically stable

Question 7

what makes hemiacetals?

Answer 7

an aldehyde group and an alcohol

Question 8

how are sugar alcohols formed?

Answer 8

by a reduction reaction of the aldehyde group of glucose to a hydroxyl group

Question 9

what are sugar alcohols used in?

Answer 9

theyre used in food suitable for diabetics as its sweet tasting but doesn’t have glucose in it

Question 10

what is the difference in energy between glucose and sugar alcohol?

Answer 10

the energy in sugar alcohols is about half the energy of glucose

Question 11

what do phosphorylated sugars do?

Answer 11

they can be taken up by the cell, then go thought the cell and then diffuse back out so it is phosphorylated

Question 12

how are phosphorylated sugars made?

Answer 12

theyre made by the addition of a phosphoric group onto a monoaccharide- this makes the sugar anionic to trap the sugars within the cell and create a reactive intermediate in sugar metabolism

Question 13

how many monosaccharides do disaccharides have? and what type of reaction forms them?

Answer 13

2- and theyre formed by a condensation reaction

Question 14

how many monosaccharides form oligosaccharides?

Answer 14

3-10

Question 15

are olgiosaccharides digestable?

Answer 15

no, thyre not usually digestable

Question 16

where are intrinsic sugars found?

Answer 16

theyre contained within the plant cell wall

Question 17

Where are extrinsic sugars found?

Answer 17

theyre free in sloution
these are the bad ones that cause plaque and cavities

Question 18

what are the most common simple sugars?

Answer 18

sucrose (made from 1 glucose and one frutose)
fructose
maltose
lactose (made from one glucose and one galactose)
mannose
glucose

Question 19

where do sucrose and lactose come from? (they come from different places)

Answer 19

lactose- milk sugar
sucrose- cane sugar

Question 20

what is the formula for simple sugars?

Answer 20

C12H22O11

Question 21

when is glucose osmotically active?

Answer 21

its osmotically active until you have lots of glucose molecules together then its not

Question 22

how many sugars make up nutritionallu important disaccharides?

Answer 22

2

Question 23

name some nutritionally imoirtant disaccharides? and what are they made up of?

Answer 23

sucrose (glycosyl-fructose)
isomaltose (isoform of maltose linked 1-6)
lactose (galactosyl-glucose)
maltose (glucosyl-glycose)
trehalose (glycosyl-glucose)

Question 24

what are polysaccharides?

Answer 24

theyre sugars made up of more than 2 sugars

Question 25

what are some polysaccharides?

Answer 25

starch - this has a variable no. of glucose units)
amylose - this is a chain of glucose molecules
amylopenctin- this is a chain of glucose molecules and every 30th one, the glucose branches to other glucose residues
glycogen- this is similar to amylopectin but instead its every 10th one
non-starch polysacchrides- these cant be digested by human enzymes, but can be digested by the human digestion

Question 26

how can we digest starch?

Answer 26

you need to cook it to be able to break it down and get the energy out of it
uncooked starch is resistant to digestion because it presents as small, insoluble granules

Question 27

what does the hydrolysis of starch by amylase result in?

Answer 27

the amylase is founs in the saliva and pancreatic juices and they result in the formation of dextrins then glucose, maltose and isomaltose