Animal nutrition- Carbs and Lipid metabolism

What are the major sources of energy in animal diets?

Carbohydrates and lipids

Starch digestion process

It is the major carb and digested and absorbed in the small intestine as glucose

Starch= broken down by amylase, made into maltose and broken down by maltose into glucose

Fats main function

Provide energy to make ATP

What are the three major monosaccharides?

Glucose, galactose, and fructose

What are the most common disaccharides?

Sucrose, Lactose, and maltose

Sucrose= table sugar that gets broken down into glucose

Lactose= from milk and then broken down into glucose

Maltose= broken down to glucose

Blood glucose

All the sugar that goes into your blood stream; when glucose is absorbed in small intestine, then goes through liver to be filtered and then the blood glucose travels throughout your body to power organs and brain

Highest one hour after eating carbohydrates

Gluco

Glucose

Glyco

Sugar

Lipo

Lipid

Keto

Ketone

Hyper

High

Hypo

Low

Lysis

Dissolution/ breakdown

Genesis

Creation/ synthesis

Emia

Presence of a substance in blood

Neo

New

What tissues need nutrients all the time?

Red blood cells and brain tissues

What tissues need nutrients based on activity levels

Muscle tissues and mammary glands need nutrients not based on their food intake but activity level

What happens during the absorptive period?

Animal has to deal with an abundance and store and use nutrients as quickly as possible

Glycolysis

Purpose: Obtain ATP to fuel metabolism and generate pyruvate to oxidize further

Glucose is broken down to pyruvate and ATP and NADH In cytosol and activity is related to activity of cell

Pyruvate and NAD goes into mitochondria for the Krebs cycle

Anaerobic glycolysis

The main purpose is to obtain ATP quickly without using oxygen

In red blood cells do not have mitochondria or oxygen so pyruvate is made into lactose so it can restore NAD

Pentose phosphate pathway (HMP pathway)

Purpose: Generating NADPH (catalyzes fatty acid biosynthesis) and used to make sugars Ike ribose for RNA/DNA

In cytosol, NADPH needs a lot of glucose so if adipose cells make fatty acids, those cells will use glucose to make NADPH

TCA cycle (Krebs cycle)

Purpose: When coupled with the ETC, this generates a lot of ATP and helps all compounds that can be oxidized; also helps make the non essential amino acids

Reaction: in mitochondria and it oxidizes the pyruvate acid produced from glycolysis

ETC

Purpose: Generate ATP and produce NAD to keep the TCA cycle running

Inner membrane of the mitochondria where NADH is oxidized and oxygen is reduced to water and the energy is captured in the high energy bond of ATP

Glycogen synthesis and breakdown

Main point is to join glucose together to store them as glycogen in liver when glucose is abundant and then broken down so that it is available and a ready source of blood glucose later when glucose is not being absorbed

Glycogen can be stored in muscles for later conversion to glucose for use in glycolysis

Animals can also make glycogen directly from proteins (cats)

Lactose synthesis

Lactose is made into the mammary gland of mammals and it is to provide easily digested carbs for the neonate

Triglyceride formation

3 fatty acids are linked to a glycerol backbone

Purpose: triglycerides are formed for long term storage of chemical energy after a meal and stored in adipose tissue

Also used for transferring fatty acids to suckling neonate and can form in the mammary gland and it will be dependent on when milk is being synthesized

Lipogenesis

Also known as fatty acid synthesis

Break down glucose to acetyl cos and use it to make fatty acids

Fatty acids are made in cytosol and a meal high in carbs and low in lipid so fatty acids are produced form glucose for long term energy storage or transfer to suckling neonate

Gluconeogensis

This si the synthesis of glucose from non-carb sources

The compounds must be C3 or more and anything converted into TCA cycle can be used but also all amino acids, Propionic acid, glycerol, lactic acid

Really important in ruminants and foregut fermenters because most starch is fermented in rumen so little glucose is absorbed and important for carnivores

Cori cycle

Conversion of glucose to lactic acid in tissues during anaerobic exercise and then convert lactate to glucose in liver

Purpose: shift part of metabolic burden of active muscles to the liver and to enable red blood cells to be smalle effective oxygen carriers

No net products are made