Carbohydrates

Question 1

Carbohydrates

Answer 1

function as the energy sources for the body

Question 2

3 classes of nutrients that supply energy

Answer 2

-CHO
-Fat
-Protein

Question 3

Carbohydrates are produced by nature where?

Answer 3

in plants

Question 4

How are carbohydrates classified?

Answer 4

on a basis number of sugar units:
-mono-
-di-
-tri-
-polysaccharides

Question 5

Monosaccharides

Answer 5

simple sugars subclassed according to number of C’s in chain: triose, tetrose, pentose, hexose

Question 6

Hexoses

Answer 6

-mono
-play a significant role in nutrition both as food components and as products of body metabolism

Question 7

Glucose

Answer 7

-hexose
-occurs free in nature (dextrose)
-principle energy source in plood
= principle enrgy source metabolized by the body
-principle component of starch and cellulose

Question 8

Galactose

Answer 8

-does not occur free in nature only as part of a disaccharide

Question 9

Fructose

Answer 9

-a ketohexose, occurs in small amounts in fruits honey, and plant juices
-the sweetest of all sugars

Question 10

Mannose

Answer 10

occurs in plants as mannans

Question 11

Pentoses

Answer 11

-very small amount in free form

Question 12

Arabinose

Answer 12

little significance
-in polymer form
-a component of gums

Question 13

Xylose

Answer 13

-trace in free form
-hydrolysis of fibrous material such as hay, oats, corn cobs, woods yield xylose

Question 14

Ribose

Answer 14

-little in free form
-component of ATP, DNA, riboflavin, RNA, ADP
-can be synthesized by animal

Question 15

Trioses

Answer 15

important intermediates in metabolism of CHO but do not occur in nature

Question 16

Disaccharides

Answer 16

-maltose
-sucrose
-lactose
-cellubiose

Question 17

Maltose

Answer 17

2 molecules of D-glucose attached in an alpha 1-4 linkage

Question 18

Sucrose

Answer 18

glucose + fructose
-used to improve palatability and physical nature of diet

Question 19

Lactose

Answer 19

-milk sugar, product of the mammary glands
-galactose + glucose
-one of the main energy sources in young mammals
-more slowly hydrolysizd in GI tract
-less likely to undergo acid fermentation

Question 20

Cellubiose

Answer 20

2 glucose units but in a beta 1-4 linkage
-intermediate product of cellulose digestion in ruminants

Question 21

Polysaccharides

Answer 21

-main CHO in feedstuffs’
-starch
-dextrin
-glycogen
-cellulose
-insulin

Question 22

Starch

Answer 22

-the reserve form of energy in most plants
-amylose starch (alpha 1-4 linkage)
-amylopectin starch (alpha 1-4 linkage and an alpha 1-6 branched link)

Question 23

Dextrin

Answer 23

does not occur naturally
-intermediate in the hydrolysis of starch

Question 24

Glycogen

Answer 24

animal starch
-highly branched but branches are shorter
-store more in smaller space
-found in liver and muscle

Question 25

Cellulose

Answer 25

most abundant CHO on earth
beta 1-4 linkage with little branching
mammals do not produce and enzyme to hydrolyze this molecule

Question 26

Inulin

Answer 26

polymer of fructose units

Question 27

Lignin

Answer 27

not a CHO but has similar characteristics
high resistance to any digestion so it decreases utlization of other nutrients

Question 28

Pentosans

Answer 28

polymers of pentoses

Question 29

Hemicellulose

Answer 29

more easily hydrolyzed than cellulose
chain of beta 1-4 linkages with branches of alpha 1-6 xylose units

Question 30

Amylase

Answer 30

the main source of starch digesting enzyme in pancreas

Question 31

Products of cellulose digestion

Answer 31

VFAs, CH4, and CO2

Question 32

What VFAs are produced during microbial fermentation

Answer 32

acetate, butyrate, and propionate