Chapter 24

Nutrient

 substance in food that the body uses to promote normal growth, maintenance and repair

Water

Nutrient that is essential for health body function and accounts for 60% of the total food we eat.

1. carbohydrates

2. Lipids

3. Proteins

4. Vitamins

5. Minerals

5 main nutrients

1. Carbohydrates

2. Lipids

3. Fats

macronutrients: [3]

1. Vitamins

2. Minerals

Micronutrients: [2]

Essential nutrients

40 molecules that diet must provide. Cannot be produced fast enough by the body.

Nonessential nutrients

If not enough of these nutrients are available in the body, the liver can convert into another nutrient if needed.

1. Build cell structures

2. Replace worn out parts

3. synthesize functional molecules

4. Create ATP

Nutrients are used by cells to: [4]

ATP, the chemical energy that is used in the body

Most nutrients in the body are metabolized and transformed into what?

Carbohydrate.

Nutrient that accoutns for 65% of total calorie intake.

1. Simple carbohydrates

2. Complex carbohydrates

Two kinds of carbohydrates:

Complex carbohydrates

Carbohydrates that we need in diet. Comes from bread, cereal, crackers, flour…

Simple carbohydrates

Carbohydrates that might be avoided in diet. Sugars, candy, fruit, ice cream…

Fiber

Indigestible carbohydrates:

Lipids

Nutrient that comes from animal and plant sources, makes up about 20-35% of caloric intake.

Cholesterol

Type of lipid that is created by the liver, we don’t need to take it in (should consume as little as possible)

Protein

Nutrient that accounts for 12-20% of total caloric intake. Building blocks are amino acids.

Complete proteins

Proteins that come from eggs, milk, milk products, meat, soybeans

Incomplete proteins

Proteins that come from legumes, nuts and seeds, grains and cereals, and vegetables.

Vitamin

Organic compounds that are crucial in helping body use nutrients:

Coenzyme

Role that a vitamin that when they act with an enzyme to accomplish a particular chemical task

1. Vitamin D (synthesized in the skin

2. Some B and K synthesized by intestinal bacteria

3. Beta-carotene (from carrots) converted in body to vitamin A

All vitamins can be ingested, except [3]

No one food group contains all vitamins - highlights the importance of a balanced diet

Why is a balanced diet important concerning vitamins?

1. Water-soluble

2. Fat-soluble

Types of vitamins in body based on solubility: [2]

1. A

2. D

3. E

4. K

Fat-soluble vitamins: [4]

K

All fat-soluble vitamins can be stored in the body, except vitamin ______

Water-soluble vitamins

Vitamins that cannot be stored in the body. If they are not used within an hour, are excreted.

Free radicals

Dangerous substances that are produced during normal metabolism. Vitamins counter-balance them and they are no longer dangerous.

Antioxidants

Vitamins C, E, and A along with selenium neutralize free radicals They are called:

1. Calcium

2. Phosphorus

3. Potassium

4. Sodium

5. Chloride

6. Chlorine

7. magnesum

Minerals required in moderate amounts: [7]

Urinary system

System that ensures proper levels of minerals in the blood is maintained, to prevent toxic overload:

Metabolism

Sum of all biochemical reactions inside a cell involving nutrients

Anabolism

Metabolic process involving synthesis of large molecules from smaller ones

Catabolism:

Metabolic breakdown of complex structures to simpler ones

1. Glycolysis

2. The citric acid (Krebb’s) cycle

3. Oxidative phosphorylation

Three key catabolic processes involved in cellular respiration:

Cellular respiration

Process of deriving energy from the food we eat. Results in the breakdown of food fuels to form ATP.

1. Glycogen

2. Fats

How can energy (glucose) be stored: [2]

digestion and absorption in GI tract

Nutrients are then transported to blood cells.

No nutrients in blood, metabolism does not work

Describe stage 1 of metabolism

1. Nutrients are built into lipids, proteins, and glycogen

2. Nutrients can be broken down into smaller particles

One of two things can happen in the cytoplasm of tissue cells during stage 2 of metabolism:

Pyruvic acid

Most substances that get broken down during the second stage of metabolism end up as what?

Process is almost entirely catabolic

Requires oxygen and gives off CO2

Results in a large amount of ATP being created

Describe stage 3 of metabolism:

Carbohydrates. once digested, carbs are ultimately transformed into glucose (the body’s main energy source)

The body’s “go-to” energy source is

Insulin

Hormone that assists glucose to get into cells. Released by pancreatic islet cells

Insulin increases active transport of amino acids into cells that increase protein synthesis

effect of insulin on protein synthesis:

Glycogenolysis

process happening in the liver. Breakdown of glycogen in the liver releasing glucose into the bloodstream. Increased blood glucose levels

Glucogenesis

Process happening in the liver. Creation of new glucose from other substences. Resulting in more glucose being released into the blood stream.

1. Glycogenolysis

2. Glucogenesis

3. Stimulates fat to be used instead of glucose for energy

Processes stimulated by glucagon: [3]

Fats

Body’s most concentrated source of energy:

lymph

How are products of fat transported for the most part?

Triglycerides, broken down into glycerol and fatty acids.

Main lipid used for energy:

1. Part of glycolysis

2. Oxidative phosphorylation

What pathway of cellular respiration do fats feed into?

1. Fatty deposits provides cushioning

2. Use lipids to build cell membrane

3. Important part of myelin sheath

4. Ovaries, testes, and adrenal cortex use cholesterol to produce hormones

5. Absorb fat-soluble vitamins

6. Numerous functions of the liver (forming bile salts)

Functions of lipids, excluding energy source: [6]

To build new proteins. Much of cell structure is protein-based. Can be used to build or repair structures.

Why does the body require amino-acids?

1. used for energy (when carbs and lipids are unavailable) and

2. Stored as fat

Excess proteins cannot be stored. They are either: [2]

Process occurs in the liver

How are amino acids used as an energy source? [through which organ}?

1. Produces bile

2. Processes nearly every class of nutrient

3. Absorbs and stores glucose as glycogen

4. Regulating plasma cholesterol levels

5. Stores vitamins and minerals

6. Filters blood (detoxifies)

7. Metabolizes alcohol, drugs, hormones, and bilirubin.

Metabolic functions of the liver (it has over 500, but name ones mentioned in class)