Chapter 24: Nutrition

Macronutrients

supply the body with energy (kilocalories)

Micronutrients

help manufacture, repair, and maintain cells

Anabolism

formation of large molecules from smaller ones

Catabolism

breakdown of larger molecules into smaller components

The process of catabolism releases

energy

Anabolism requires

energy

A kilocalorie is

the amnt of heat required to raise one kilogram of water 1 degree C

Macronutrients include

1. carbs

2. proteins

3. fats

Micronutrients include

1. vitamins

2. minerals

Chemical formula for carbs

CHO

Simple carbs are named by the amount of ___ units making up their chemical structure

sugar (saccharide)

Carbs function

1. supply energy for muscle and organ function

2. spare proteins

3. play a role in nutrition and metabolism

More easily and quickly ingested macronutrient

carbs

Simple carbs e.g.

1. sugars

2. honey

3. fruit

4. milk

Complex carbs e.g.

1. bread

2. pasta

3. rice

4. potatoes

Enzymes involved in carb digestion

1. salivary amylase

2. ptyalin (mouth & stomach)

3. pancreatic amylopsin

4. intestinal sucrase, lactase, maltase

Glycogen

glucose stored in liver and skeletal muscle tissue

Carbs act as a ____ sparing function

protein

Carbs are important in oxidizing fats in

normal fat metabolism

Carbs promote desirable bacteria growth in the

intestine

Carbs yield about

4 kcal

Carbs are important in enhancing the secretion of

insulin

Insulin promotes

the movement of glucose into cells for use

Carbs promote the absorption of

sodium

Carbs promote the excretion of

calcium

Polysaccharides not digested in the GI tract are a main component of dietary fiber (T/F)

True

Normal fasting blood sugar

60-100

Transportation of glucose is done from the

GI tract through the portal vein to the liver

Short term glucose excesses is changed into glycogen in the presence of insulin in the

liver

Longer term storage of glucose in the presence of insulin takes the form of

adipose tissue

Proteins

organic compounds composed of polymers of amino acids connected by peptide bonds

Proteins contain

1. carbon

2. hydrogen

3. oxygen

4. nitrogen

Proteins synthesized by human body

1. hemoglobin

2. insulin

3. albumins

Secondary source of energy when CHO isn’t available

protein

Protein functions

1. growth and tissue building

2. regulation of bodily functions

3. regulate immune system, digestion, absorption, metabolism, and catabolism

Protein yield about

4 kcal

Essential amino acids must be supplied by

food or nutritional supplements

Essential amino acids are produced within the body (T/F)

False

Complete proteins

contain sufficient amounts of essential amino acids to maintain body tissues and promote growth

Incomplete proteins

do not contain sufficient amino acids to maintain life, build tissue, or promote growth

Incomplete protein e.g.

nuts and grains

A complete protein can be made by

combining two incomplete proteins

Proteins are broken down into amino acid particles by pancreatic enzymes in the

small intestine

Excess amino acids are converted into

1. fatty acids

2. ketone bodies

3. glucose

Anabolism builds

tissue, produces antibodies, replaces blood cells, and repairs tissue

Enzymes involved in digestion of proteins

1. pepsin (stomach)

2. trypsin, chymotrypsin, carboxypeptidase (pancreas)

3. aminopeptidase, dipeptidase (intestine)

Function of protein

1. tissue building

2. metabolism

3. immune system function

4. fluid balance

5. acid-base balance

6. secondary energy source

Positive nitrogen balance creates a pool of amino acids available for

1. growth

2. pregnancy

3. tissue maintenance and repair

Negative nitrogen balance occurs during

1. illness

2. injury

3. malnutrition

Proteins are precursors to

digestive enzymes and hormones

Lymphocytes and antibodies are not proteins (T/F)

False

Proteins ___ water, therefore they help to regulate fluid balance

attract

Blood proteins act as

buffers

Lipids are composed up of

1. carbon

2. hydrogen

3. oxygen

Lipids should make up about ___ % of body weight

20

Lipids are needed for

1. cellular transport

2. nerve-impulse transmissions

3. insulation

4. organ protection

5. energy provision

6. absorption and transportation of some vitamins

Lipids supply about

9 kcal

This remains in the stomach longer than carbs and proteins

lipids

Number of ___ hydrogen molecules bound to the fat decide if a lipid is saturated or unsaturated

hydrogen

Saturated fats are ___ at room temp

solid

Sources of saturated fats include

1. animal products

2. cheeses

3. plant sources (coconut oil, cocoa butter)

Unsaturated fats are ___ at room temp.

liquid

Sources of unsaturated fats

1. corn

2. olive

3. soybean/sunflower oils

4. nuts

Trans-fatty acids are created when

fat is altered by being solidified, making it have a longer shelf life

Trans-fat e.g.

1. margarine

2. fast foods

3. commercial baked goods

Three types of lipids

1. glycerides

2. sterols

3. phospholipids

True fats are

glycerides

Main glycerides found in foods

triglycerides

Sterols

lipids not made up of fatty acids

Most important sterol in human body

cholesterol

Cholesterol is synthesized in

liver

Low density lipoproteins (LDLs) transport

cholesterol to body cells

“Bad cholesterol” is known as

LDLs

An increase in LDLs circulating in the bloodstream can be caused by a diet high in

saturated fats

High-density lipoproteins (HDLs) remove

cholesterol from the bloodstream, returning it to liver, where it is used to create bile

“Good cholesterol” is

HDL

Lipid digestion occurs in

small intestine

Bile emulsifies fat to

increase the surface area so that pancreatic lipase can break down fat more effectively

More fats are absorbed into the

lymphatic circulation and are transported to the liver

Cholesterol is an ingredient of

bile

Bile functions

1. fat digestion

2. precursor to all steroid hormones

Vitamins

organic compounds essential to the body in small quantities

Vitamins functions

1. growth

2. development

3. maintenance

4. reproduction

5. regulate body functions

Most vitamins can by synthesized by the body (T/F)

False

Fat soluble vitamins e.g.

1. A

2. D

3. E

4. K

Fat soluble vitamins can be stored in the body (T/F)

True

Fat soluble toxicity cannot occur (T/F)

False

Vitamin A forms

1. preformed vitamin a (retinol); complete

2. provitamin a (found in beta-carotine); incomplete

Vitamin A function

1. vision

2. healthy epithelium

3. promotion of normal skeletal and tooth development

4. normal cellular proliferation

Vitamin A deficiency signs

1. night or total blindness

2. epithelial changes

3. skin changes

4. inadequate tooth and bone development

Carotenemia

vitamin a toxicity that leads to yellow skin

Hypervitaminosis A

vitamin a toxicity that causes headaches, blurred vision, pain in bones and joints, dry skin, and poor appetite

Vitamin a food sources

1. yellow vegetables

2. fish oils

3. fortified milk and dairy products

Vitamin D functions

1. intestinal absorption of calcium

2. mobilization of calcium and phosphorus from bone

3. renal transport of calcium

Vitamin D deficiency causes

1. rickets in children

2. poor dental health

3. tetany

4. osteomalacia

Vitamin D toxicity

1. loss of appetite, nausea, vomitting

2. polyuria

3. muscular weakness

4. constipation

Vitamin D food sources

1. fortified milk

2. cereals

3. fish

Vitamin E functions

1. antioxidant (protects integrity of cellular membranes)

2. protects RBCs and muscle tissue

Vitamin E deficiency leads to

1. increase hemolysis of RBCs

2. poor reflexes

3. impaired neuromuscular functioning

Vitamin E toxicity leads to

1. excessive bleeding

2. impaired wound healing

3. depression