Nutrition Exam 2

what are lipids?

compounds that contain carbon, oxygen, and hydrogen

are lipids hydrophilic or hydrophobic?

hydrophobic

what is the common name for one type of lipid?

fat

what else is a lipid known as?

a triglyceride

food labels and nutrition sources generally refer to this category as blank rather than blank

dietary fat rather than dietary lipid

what does fat do in cooking?

increases flavor and contributes to satiety

Fats are essential for

energy storage and insulation

two types of lipids are important components of your blank and play a role in

cells…transporting compounds in your blood

what are three types of lipids found in foods and in your body?

triglycerides (fats), phospholipids, and sterols

fatty acids are found in

triglycerides and phospholipids

monounsaturated fatty acids have how many double bonds?

one

An unsaturated fatty acid has

one or more double bonds between carbons.

Polyunsaturated fatty acids (PUFAs) have (how many) double bonds

two or more

essential fatty acids must be consumed where?

in the diet

what are two essential fatty acids?

linoleic acid and alpha-linolenic acid

triglycerides contain

three fatty acid chains connected to a glycerol backbone

the more common name for triglycerides is

fat

phospholipids have

two fatty acids and a phosphate group connected to a glycerol backbone

phospholipids make up the (blank) in cell membranes

phospholipid bilayer

The major phospholipid in your cell membranes is

lecithin

Lecithin is often used in foods, such as salad dressings, as an

emulsifier

sterols are composed of mainly

four connecting rings of carbon and hydrogen

The best-known sterol is

cholesterol

eating cholesterol (equals or doesn’t equal) high blood cholesterol

doesn’t equal

what is more likely to raise LDL levels?

saturated and trans fat intake

The digestion of fat begins in the (blank) with the enzyme (blank)

mouth…lingual lipase

what does peristalsis do with fat in the stomach?

mixes and churns the fat containing food with gastric jui ces

what does gastric lipase do w fat in the stomach?

breaks down some fats, creating diglycerides and free fatty acids

where does the majority of fat digestion happen

in the small intestine, where fat is broken down into two fatty acids and a monoglyceride.

Bile is secreted from the (blank) through the (blank) into the (blank)

gallbladder…common bile duct…small intestine

bile does what to fat?

emulsifies it into smaller globules

what breaks down fats into monoglycerides, glycerol, and free fatty acids?

pancreatic lipase

By-products of fat digestion are packaged into (blank) for (balnk) through the cells of the intestinal wall

micelles…transport

Short chain fatty acids enter blood stream

directly

Long-chain fatty acids are packaged as (blank) and travel in the (blank) before entering the bloodstream to deliver fat to your cells.

lipoproteins…lymph

Chylomicrons

transfer fat after a meal

VLDLs

deliver fat made in your liver to your cells

LDLs

deposit cholesterol in the walls of your arteries

HDLs

remove cholesterol from your body and deliver it to the liver

Chylomicrons transfer blank and blank from a meal via the blank to your cells

fat…cholesterol…lymphatic system

Blank helps break down fat

Lipoprotein lipase (LPL)

LPL in adipose tissue:

active after eating → fat storage

LPL in muscle/heart:

active during fasting → fat burning for energy

remaining chylomicron is dismantled in the

liver

VLDLs are produced in the blank and deliver fat to blank and blank tissue

liver…adipose…muscle

Lipoprotein lipase helps with the

uptake of fatty acids into the cells

what is VLDL broken down into?

LDL (low-density-lipoprotein)

LDLs are produced in the blank as a result of blank

bloodstream…VLDL metabolism

what does LDL do?

Release cholesterol to tissues, into body cells (“Bad cholesterol”)

LDL not taken up by cells

degrade and release cholesterol that adheres to the blood vessel walls = plaque formation in the arteries

HDLs are produced by the blank and circulate the blood = good or bad

liver…good

what does HDL do?

picks up cholesterol from cells, returns it to the liver where it is excreted through bile and removed from the bloodstream

fat provides

energy

the body has a blank ability to store excess calories as fat

unlimited

fats help you absorb..and blank the body

fat-soluble vitamins A, D, E, K…insulates

Linoleic acid is an…and it is used to make blank, which is important for making eicosanoids

omega-6 fatty acid…arachidonic acid

alpha-linolenic acid is an…and a limited amount can be converted to…which can reduce the risk of…

omega-3 fatty acid…EPA and DHA…heart disease and stuff

All fish contain

EPA and DHA

Fish intake for adults:

Adequate intake for adults: 500mg/day

8 oz fatty fish (2 meals) per week

Limit fish oil supplements to 2 grams/day

cholesterol is part of your

cell membranes

cholesterol is the precursor for

vitamin D, bile acids, and sex hormones

what is the AMDR for fat?

20 to 35 percent of daily calories

A minimum of blank percent of total calories should come from lineoleic acid, and alpha-linolenic acid should make up blank to blank percent

5-10%…0.6-1.2%

what percentage of sat and trans fats should you be consuming in your diet?

below 10%

what are sources of sat fats?

solid fats

trans fats are created through the process of

hydrogenation

which are worse: trans or saturated fats?

trans

8 types of hydrogenated oils:

corn, canola, cottonseed, soy, sunflower, safflower, grapeseed, ricebran

what was the first study to demonstrate that heart disease begins in childhood?

The Bogalusa Heart Study…also physical and lifestyle attributes contribute to developing heart disease

blank is the leading cause of death in the U.S.

Cardiovascular disease (CVD)

LDLs can lead to

atherosclerosis

artherosclerosis is a major risk factor for

heart attack and stroke

artherosclerosis in cerebral arteries is a contributing factor to

Alzheimer disease

some CVD risk factors can’t be modified like

family history of heart disease, race, age, gender

and some CVD risk factors can be modified like

smoking, diet, lifestyle, obesity, diabetes, alcohol, high BP, and high cholesterol, LDL, and triglyceride levels

appropriate diet and lifestyle choice may reduce our risk for CVD by about

80%

what is the only type of lipid where if high, it’s a good thing?

HDLs

what is a cluster of risk factors associated with CVD and type 2 diabetes?

large waistline, high triglyceride levels, low HDL cholesterol levels, high blood pressure, high fasting blood sugar (having at least 3 risk factors is diagnostic of metabolic syndrome)

sources of sat fat in the US

what are proteins?

predominant structural and functional materuals in cells

the building blocks of proteins are

amino acids

there are blank different and unique amino acids

20

what are peptides?

Amino acid chain that contains fewer than 50 amino acids linked together

two joined amino acids form a

dipeptide

three amino acids form a

tripeptide

A polypeptode is more than blank amino acids joined together

10

more than blank amino acids =

protein

what is the anatomy of an amino acid?

a central carbon surrounded by an acid group, an amine group, a hydrogen atom, and a unique side chain

how many essential amino acids are there, what are they called and what do they mean?

9…VH MILK WTF…cannot be made by the body and must be obtained from the diet

how many nonessential amino acids are there, and what do they mean?

11…they can be synthesized by the body

what are conditionally essential amino acids?

normally nonessential but become essential during illness or when precursors/enzymes are lacking

proteins can be denatured by

heats, acids, bases, or mechanical agitation

denaturation of a protein changes what but does not affect what

shape…the sequence of amino acids

any change in shape of a protein will alter its

function

where does digestion of proteins begin and what type is it

mechanical digestion in the moth; chewing, tearing, and mixing with salivary juices

what happens to proteins in the stomach?

HCl denatures them and activates pepsinogen to form pepsin which breaks polypeptide chaims into smaller polypeptides

what happens to proteins in the small intestine?

enzymes from pancreas are released into the small intestine, peptide bonds are borken from polypeptides to di- and tri- peptides and single aa’s, enzymes in lining of si finish digestion to yield single aa’s and aa’s are absorbed in the bloodstream and travel to the liver

which enzymes produced by the pancreas are released into the small intestine?

trypsin, chymotrypsin, and carboxypeptidase

the process of continually degrading and synthesizing protein is called

protein turnover

what and what contain a small supply of aa’s in what that constantly change as the body degrades and synthesizes protein

blood…cells…amino acid pools