Exam 2 - Human Nutrition - Based on the canvas info

What are the five primary functions of lipids?

energy storage, cell membrane structure, hormone signaling, insulation, and absorption of fat-soluble vitamins.

What is the primary lipid component in cell membranes?

phospholipids

What is the chemical structure of a phospholipid?

Water soluble head (hydrophilic), two fatty acid chains, glycerol backbone,

What is cholesterol?

It is a waxy, fat-like substance that is an essential component of cell membranes and plays a role in the production of bile acids, vitamin D, and steroid hormones.

Is Cholesterol a non-essential lipid?

Yes, because it is produced by the body.

Triglycerides are the ____ abundant lipid in our diet.

most

Are Triglycerides a storage form of fat in our bodies?

Yes

What is the chemical structure of Triglycerides?

Three fatty acid chains, connected to a glycerol molecule, the "head" is a glycerol molecule, which is a polar, hydrophilic (water-loving) component, while the "tails" are three fatty acid chains, which are nonpolar and hydrophobic (water-repelling).

Sterols

Cholesterol is the primary dietary sterol.

Saturated vs Unsaturated fatty acids

the chemical structure in saturated, no double bonds between carbon atoms, fully saturated with hydrogen atoms. Physical state, solid at room temp. Unsaturated: one or more double bonds between carbon atoms. Physical state, liquid at room temp.

Role of bile acids vs Lipase

bile acids are produced in the liver, lipase is produced by the pancreas.

Bile acids emulsify fats by creating tiny droplets. Lipase is the enzyme that chemically breaks down the fat molecules.

What are the two essential fatty acids?

Omega-3, and Omega-6 fatty acids

What are the most recommended lipids for the typical american diet?

Seafood omega-3 fatty acids

What is the primary GI site for fat absorption?

Small intestine

What are four lipoproteins?

LDL (low-density lipoproteins), VLDL (very low-density lipoproteins), HDL (high-density lipoproteins), and ChylomicronWhere

Among the four lipoproteins ____ picks up cholesterol from the body cells and returns them to the liver.

HDL

Where does chylomicron originate from?

Small intestine

Both chylomicron and VLDL transport primarily _____

Triglycerides

VLDL originates from the ______

Liver

HDLs originate from where

Small Intestine

Where do LDL cells come from?

The Liver

What lipoprotein has the highest percent of triglyceriddes?

Chylomicron

What lipoprotein has the highest percent of protein?

HDL

What is the AMDR for dietary lipids?

20-35%

According to the acceptable Macronutrient Distribution Rages(AMDRs), what is the minimum amount of trans fat in grams recommended for an 3600-calorie diet? 9 calories/g fat

3600 x .02 = 720

720/9 = 80 g

According to the AMDRs, what is the maximum amount of fat in grams recommended for an 900-calorie diet? 9 calories/g fat

900 x .02 = 18

18/9 = 2 grams

What are the dietary resources of trans fat?

Partially hydrogenation not fully hydrogenation

What is the chemical structure of trans fat?

Unsaturated fats with trans double bonds instead of cis-bonds, creates a straight fatty acid chain not a bent one.

Most of the unsaturated fatty acids found in nature are _____

cis fats

What are the harmful effects of consuming trans fats?

Raise levels of LDL cholesterol and lower levels of HDL cholesterol in the blood. This increases the risk of heart disease more than any type of fat. As little as 1% of total calories from trans fat can increase risk of heart diseases, stroke, or sudden death from these illnesses.

What was the most important finding in the Bogalusa Heart Study?

Fat plaques form in the vessels of children.

Cardiovascular disease (CVD) is ____ term

Long term, not developed over night. The long-term narrowing (affecting blood flow) and loss of elasticity (increasing blood pressure) in blood vessels.

When does CVD develop

It develops over many years often beginning in childhood.

How is the plaque formed in CVD?

LDLs accumulate in the blood, they become oxidized, which causes inflamantion and inqury to the vessel wall. Plaque begins as lipids from LDL accumulate here.

What does plaque in a vessel lead to in CVD?

The plaque will slowly build up more over time leading to a plaque rupture or clot formation that will further block blood flow through the artery. This leads to a heart attack, when an artery supplying blood to the heart is completely clot. Or a stroke, when an artery supplying blood to the brain is completely clot.

Modifiable risk factors for CVD?

Diet, obesity, activity, smoking, alcohol consumption, Heart-related conditions (high blood pressure, blood glucose, LDL cholesterol)

Dietary suggestion for CVD?

Keep saturated fats below 7% of calories but do not completely eliminate saturated fat from the diet.

what are the functions of proteins?

structural support, biochemical catalysts, hormones, enzymes, building blocks, initiators of cellular death.

What is the primary function of amino acids?

They are the building blocks for protein. Amino acids form proteins through peptide bonds.

Are there essential and non-essential amino acids?

Yes

What is the chemical structure of amino acids?

Central carbon, amino group, carboxyl group, and R-group(side chain) the side chain is the difference between each amino acid.

How can the r-group in amino acids differ

polar, non-polar, charged

What is protein denaturation?

the process of changing the three-dimensional structure of protein. Its second and third structure are destoryed but first remains intact.

what are the factors that cause protein denaturation?

heat (high temps), acids and bases (changes in pH), alcohol, salt, mechanical agitation, UV light, reducing and oxidizing agents, heavy metal ions.

What is the main purpose of protein turnover in the body?

to maintain a constant supply of functional proteins by continuously breaking down old or damaged proteins and replacing them with new ones. Eliminates damaged proteins.

The protein recommendation for elderly individuals over 65 years old to help maintain lean body mass is ____

1.2 g/kg/day

EX: Protein RDA for a healthy adult is .8 g/kg/day. What is the protein RDA (in grams) for an adult who weighs 154 punds, assuming the adult is not an athlete and is at a healthy body weight? (2.2 lb = 1kg)

What is the function of acidic juices?

To help break down proteins during digestion, in the stomach

What is the function of pepsin?

breaks down protein molecules by cleaving peptide bonds. In the stomach

What is the function of protease?

an enzyme that breaks down proteins into smaller peptides or amino acids by cleaving peptide bonds in the protein chain. In the stomach.

Proteins are digested into individual amino acids and enter the _______

blood stream

What is the fate of amino acids?

Excess amino acids are not stored in the body, they are broken down to C+ amino group

what is nitrogen balance

the difference between the amount of nitrogen consumed through diet and the amount of nitrogen excreted from the body. Positive means more protein is being gained and negative means more protein is being lost.

Which individuals are least likely to have a positive nitrogen balance?

a growing child

What is a complete protein?

a food source that contains all nine essential amino acids that the body needs to function. (meat, poultry, fish, eggs, dairy products, soy quinoa, buckwheat)

Can incomplete proteins be combined to form a complete protein source?

No

Kwashiorkor what is it

Acute protein-Energy Malnutrition (PEM), gets enough calories but not enough protien

Symptoms of Kwashiorkor

Wasting(loss of muscle mass), fatty liver, edema (swelling)

Marasmus what is it

a severe and prolonged deficiency of both calorie and protein intake

Marasmus symptoms

“skin and bones“, fat depletion, muscle wasting, impaired brain development + learning ability, little activity

Which is not a primary function of lipids

Acts as enzymes

What fatty acid would be the most solid at room temp?

Coconut oil

What is responsible for breaking down triglycerides into monoglycerides and free fatty acids

Pancreatic lipase

What is the correct path of an absorbed triglyceride

Chylomicron, micelle, lymph, bloodstream, liver, vldl, ldl, back to liver

Chylomicrons are synthesized within the

Liver

According to amdrs what is the maximum amount of fat grams g recommended for a 1800 kcalorie diet?

70

Lecitithin is a sterol which is used commercially as an emulaifier

Phospholipid, emulsifier

Characteristics of hydrogenated oils include all of the following except

They are converted to a form of cholesterol during the hydrogenation process

What is the less abundant fatty acid in American diet

Omega 3

What is the correct order for the stages of development of atherosclerosis

Ldl cholesterol is oxidized, foam cells form, plaque forms, blockage of arteries

Two proteins contain the same number of the 20 different amino acid, yet they do not have the same three dimensional structure and function. This is because

The proteins differ in the sequence of amino acid in the polypeptide chain.

What is true about protein digestion

Stomach acid unfold a protein, individual amino acid leave the mucosal cells through transport proteins and enter the blood, brush border proteases digest short peptides into tripeptide, dipeptides and individual amino acids

The amdr for protein intake is

10-35 total calories

What individual is not in positive nitrogen balance

A 35 year old man on a high protein diet with normal levels of physical activity

Cofactors are often

Minerals

Coenzymes are often

Vitamins

Enzymes are what that facilitate chemical reactions without being altered thenselves

Proteins

What type of reaction make up metabolism and are used to generate atp

Redox reactions

Clycolysis creates how many pyruvates

2

Glycolysis creates how many atp

2

The citric acid cycle occurs in the

Mitochondrial matrix

What metabolic pathway produces the most atp from a molecule of glucose

Electron transport train

At the completion of the citric acid cycle, the majority of the chemical energy that was originally present in the metabolic fuels is now found in

Reduced coenzymes