Nutrition 1020 Exam 3 Weber State

Mechanical digestion

The breaking down of big food parts into smaller ones, involving muscles and nerves. Chewing(mastication)

Chemical digestion

The breaking down of big food parts into smaller ones, involving acid, enzymes, and hormones. Saliva and amylase(breaks down carbs).

What is an Enzyme?

Protein that catalyze metabolic reactions, and are necessary for most biochemical reactions to occur.

Examples of enzymes

amylase:carbohydrates
protease:proteins
lipase: Lipids/Fats

What is a Hormone?

Chemicals produced by cells, and secreted, then affect the behavior of cells at distal sites in the body.

Examples of hormones and purpose?

Secretin: released from duodenal cells and sends signals to the pancreas to secrete digestive enzymes to the stomach to produce pepsin, a protease enzyme, and to the liver to produce bile.
Cholecystokinin: released form duodenal cells and sends signals to the pancreas to secrete digestive enzymes to the gallbladder to release bile.

Peristalsis

a muscular wave action that occurs throughout the intestinal tract.

Stomach

muscular organ and storage reservoir. It mechanically digests food by mixing and churning. Chemically digests food with acid and some enzymes(pepsin). The food then becomes chyme

Small Intestine Order

Duodenum
Jejunum
Ileum

The 3 accessory Organs and functions

Liver: makes bile
Gallbladder: stores bile
Pancreas: Makes enzymes, and makes sodium bicarbonate to neutralize stomach acid

Function of Bile

Emulsifier:brings the fat to the enzymes

Passive(simple) Diffusion(transport)

products pass freely across membrane, no energy

Facilitated Diffusion(transport)

water soluble vitamins diffuse across membrane using a specific proteins, needs a protein but no energy

Active Transport

glucose and amino acids move across membrane against a concentration gradient using a specific protein, and energy.

Duodenum absorbs what?

many nutrients

Jejunum absorbs what?

many nutrients

Ileum absorbs what?

only selected nutrients

Colon absorbs what?

water

Blood vessels transport what?

water soluble nutrients

Lymphatic system transport what?

fat soluble nutrients

Catabolic Reaction

breaking down, involves hydrolysis reactions. degrading and destructive in nature

Anabolic reactions

Building up, involves condensation reactions. synthesizing or constructive in nature.

Homeostasis

balance of catabolic and anabolic reactions to keep a stable internal environment of equilibrium.

What action does the enzyme lipase have on triglycerides?

Catabolic

What action does bile have on triglycerides?

neither

What action does the hormone secretin have on the liver?

anabolic

What the kidney excrets

water and water soluble waste

What the skin excrets

water and water soluble waste

What the lung excrets

carbon dioxide and water

What the colon excrets

Water is removed and waste(bacteria, fiber, etc.) is compacted

Protein Denaturation

Causes the protein to change shape or conformation. The protein and the amino acids are still intact.

What can cause protein denaturation?

heat, bases, acids, or metals

Protein Digestion

the protein strand is broken ans the amino acids are released. Amino acids are absorbed, transported to cells and then used to build proteins.

Protein synthesis

after denaturation and digestion the amino acids then proteins are made according to the DNA. Process of converting to DNA to RNA then protein.

Fibrous protein

uniform in structure, either helix or sheet formation

Globular protein

have variation in structure, part helix, part sheet or completely random

8 protein functions

1. Growth and tissue maintenance
2. Enzymes
3. Antibodies
4.Fluid and electrolyte balance
5.Acid-base balance
6. Energy
7. Protein hormones (insulin, glucagon, secretin and cholecystokinin)

The Dietary Reference Intake (DRI) for fiber for an adult is...

0.8gm/kg

The Acceptable Macronutrient Distribution Range (AMDR) for protein is...

10-35%

Kwashiorkor

Protein deficiency. An individual has peripheral edema and may not look undernourished.

Marasmus

Protein-Energy deficiency. This individual looks undernourished.

Protein Excess and risks

common in athletes and fad dieters common risks include:
Dehydration
liver and spleen enlargement
Accelerated kidney aging
metabolic acidosis
Vitamin B6 deficiency, Ca and
ZN loss
Heart disease and cancer

Photosynthesis

process by which plants make carbs structure

categories of fiber

soluble & insoluble

soluble fiber

spongey, softens in water (fruits, veggies, legumes and oats)

insoluble fiber/semi-soluble

doesn't soften or attract water (whole grain foods, celery, apple peel, CELLULOSE)

high fiber intake

over 2 g/100 caps

fiber food sources

grains, cereals, legumes, fruits and veggies

benefits of fiber in the diet

bulk (high volume food w/o cals), stool softener (food smooth along GI tract & relieves constipation), decreases transit time (more things through quicker) & helps heart health

Benefits-action of fiber

increases gastric emptying time

Negative effects of too much fiber

gas & bloating, large & frequent bowel movements, binds pos. charged minerals, binds beta-carotene (carrots), decreases caloric value, cause GI tract blockage

What is glucose used for?

energy & glycogen storage; brain function; muscle function; fat synthesis

Glycogen

Storage form of glucose; stored in the liver; used for blood sugar regulation

How does the body regulate blood sugar?

by hormones produced in pancreas: insulin & glucagon

Insulin

DECREASES blood sugar levels

Glucagon

INCREASES blood sugar levels

lactose intolerance

inability to digest lactose (milk sugar); symptoms: gas, bloating, cramps, diarrhea

allergy

immune response and involves antigens & antibodies

antibody

protein structure produced by immune cells that inactivate antigens (allergens)

Antigen

foreign protein substance that elicit immune reaction

Hypoglycemia

low blood sugar

reactive hypoglycemia

blood sugar levels drop after eating sugar

Hyperinsulinemia

the presence of excess insulin in the blood

spontaneous hypoglycemia

glycogen are depleted the ability to maintain blood sugar is diminished (btwen meals or when food has not been consumed)

drug induced hypoglycemia

low blood sugar from drug reaction

diabetes

A chronic disease characterized by hyperglycemia

Type 1 diabetes

less common, juvenile onset, more difficult to control, insulin dependent

type 2 diabetes

most common, adult onset, controlled with lifestyle changes, caused by insulin resistance

Atherosclerosis

hardening of the arteries

DASH diet

dietary approach to stop hypertension

How to reduce blood pressure

DASH diet, exercise, healthy body weight

Blood Lipids

serum cholesterol and serum triglycerides

Serum Triglycerides

elevated levels associated w heart disease, high levels thicken blood causing hypertriglyceridemia, Very Low Density Lipoproteins (VLDL)

serum cholesterol

Low Density Lipoproteins (LDL) & High Density Lipoproteins (HDL); HDLs return cholesterol to liver for synthesis of bile, hormones & vitamins; LDLs deliver cholesterol to tissue

blood cholesterol levels

total: <200 mg
LDL: <100 mg
HDL: <40 (low) >60 (high)

metabolic syndrome

if 3 + of these factors:
1.) fasting blood triglycerides lvl
2.) HDL lvl
3.) blood pressure high
4.) fasting glucose high
5.) waist circumference

Dietary Fat & Lipoproteins

SFA: increase LDL
PUFA: decrease LDL & HDL
MUFA: decrease LDL

Oxidation of Fat

double bonds of PUFAs are targets for oxidation
double bond breaks w oxidation generating lipid fragments that are sticky
sticky fragments contribute to atherosclerosis

Antioxidants

prevent oxidation reactions, react w oxygen directly and prevent heart disease

antioxidant vitamins

vitamin E, beta-carotene, and vitamin C

antioxidant minerals

zinc, copper & iron

hydrogenation of fats

trans fatty acid levels are high; double bonds from PUFAs & MUFAs removed by hydrogenation

trans fatty acids

increase LDL & decrease HDL cholesterol & increasing triglycerides

omega-3 fatty acids

good for you, reduces inflammation (salmon, herring, mackerel, tuna & whitefish)

Homocysteine

damages arteries

Lipids in Cancer

• Cancer is the 2nd leading cause of death in Americans.
• It is characterized by uncontrolled cell growth.
• It occurs through a process of initiation, promotion, and progression.

Carcinogen

initiation -> promotion -> progression

metastasis

cells split into blood stream and travel to another tissue and cancer spreads (stage 4)