Module 7 and 8

Question 1

What are carbs-?

Answer 1

Hydrated carbon- such as starch, cellulose, glycogen, lactose
Bulk of dry matter in feeds

Question 2

What is the primary monosaccharide?

Answer 2

Glucose- an energy substrate and CNS requirement- blood levels too low is diabetes- fermented to VFA in ruminants-

Question 3

What’s an aldose?

Answer 3

Monosaccharide that is an aldehyde - triose?

Question 4

What is a ketose?

Answer 4

A ketose is a monosaccharide containing one ketone group per molecule

Question 5

What are the functional groups that can occur on a carb such as glucose and fructose-?

Answer 5

Carbs can contain hydroxyl (alcohol) groups, ethers, aldehydes and/or ketones
Alkanes too-??

Question 6

Based on the # of carbon atoms in a single carb molecule, how would the carb be defined?

Answer 6

Three carbon monosaccharides are called trioses, four carbon are called tetroses, five carbon are called pentoses, six carbon are hexoses, and so on.

Question 7

When glucose structure changes from the open chain form to the more common cyclic structure, how dies this change how you would draw its structure?

Answer 7

The glucose now is more of a cynic structure- this is caused by the alpha and beta

when the hydroxyl group on carbon 5 (C5) bonds to the aldehyde carbon 1 (C1)

Question 8

What is the anomeric carbon-?

Answer 8

The cyclic form of glucose is a six-membered ring, with an intramolecular hemiacetal formed by attack of the hydroxl on the fifth carbon on the aldehyde carbon (C1) - carbon 1

Question 9

What happens when an alcohol adds to an aldehyde?

Answer 9

Hemiacetal formed

Question 10

What happens when an alcohol adds to a ketone

Answer 10

Hemiketal formed

Question 11

When starch is bonded to another to form polysaccharides, what is the specific bonding structure called for a linear chain?

Answer 11

Polysaccharide made up of glucose

**The glucose molecules are bonded together as α-(1→4) glycosidic bonds

Question 12

When cellulose is bonded to another to form polysaccharides, what is the specific bonding structure called for a linear chain?

Answer 12

Polysaccharide made up of glucose

**The glucose molecules are bonded together as β-(1→4) glycosidic bonds

Cellulose structure contains many hydrogen bonds as well, which gives it such a rigid structure

Question 13

If the polysaccharide is amylopectin [starch with a lot of branch points], or glycogen what is the other bonding that occurs in it that results in branching-?

Answer 13

Resembles amylopectin with the α(1→4) and α(1→6) branches, but there is more branching in glycogen (2.5 times more)

Question 14

What are the polysaccharides that occur in

Forages?
Grains?
Animal tissue?

Answer 14

Forages- cellulose
Grains- starch
Animal tissues- glycogen
Milk- lactose

Question 15

When glucose is metabolized by rumenal bacteria, what is the term that describes this process because it involves microbial metabolism?

Answer 15

Fermentation and the VFA when glucose is metabolized by rumen bacteria

Question 16

What are the byproducts formed that the animal makes use of when glucose is metabolized by rumen microbes?

Answer 16

VFA- the glucose in the rumen will be fermented- when microbes are done with it then it is now the byproducts

Question 17

How will the animal derive its glucose if it’s a ruminant?

Answer 17

Glycolysis

The animal can form glucose in the liver that it sends through Heptic Portal Vein

Question 18

What is propionate?

Answer 18

VFA -is glucogenic in ruminants

Propionate is converted to glucose by the liver – the “glucogenic VFA”

Question 19

What happens to the excess VFA that the animal absorbs?

Answer 19

It goes for fat production

Question 20

If the animal is a non-ruminant how is the glucose digested and absorbed?

Answer 20

In the small intestine

Amylase – digests the α(1→4) bonds
•Debranching enzyme – digests the α(1→6) bonds of branched glucose polymers
•Free glucose (and galactose) enters the intestinal cell (enterocyte) by “active transport”
•Sodium-glucose co-transporter
•ATP required to “pump” the sodium out

Question 21

What are the enzymes that are needed by the animal or the microbes if a ruminant for digestion of starches, cellulose, or the branch points of the more complex polysaccharides?

Answer 21

Starches- amalase
Cellulose- cellulase
Branch points- deb ranching enzyme-!

Question 22

What are VFAs?

Answer 22

carbohydrates --microbial fermentation--> VFA
short=chain fatty acids produced by microbes (rumen, cecum, colon)
3 types:
-acetic acid (2c)
-propionic acid (3c)
-butyric acid (4c)
absorbed passively
provide 70-80% ruminant's energy needs

Question 23

How does the animal respond to digesting carbs and absorbing glucose so that after the glucose is in the animal’s system it can be taken up by the cells of the various tissues and organs?

Answer 23

Through Glucose Transport Protein 4- Glut 4

GLUT4 is the insulin-regulated glucose transporter

Question 24

If the ruminant animal abruptly consumes a high-starch feed after having been consuming high-forage feeds for a long time, what can happen in the rumen that will ultimately affect the animals blood and its health-?

Answer 24

They can get acidosis- lactic acid buildup for decline in pH in the rumen-?

Perhaps. Perhaps not :P
Either way they’re fucked up with acidosis.