TEST THREE

Nutrition

Which nutrient requires dietary fat for absorption?

vitamins A, D, E, K

What is the most common lipid found in food and the body?

triglycerides

What structural feature distinguishes a phospholipid from a triglyceride?

it has a phosphate group instead instead of a third fatty acid

Which type of fatty acid is solid at room temperature due to tight packing?

saturated

Which fatty acids are essential and must be consumed in the diet?

linoleic and alpha-linolenic

Why are unsaturated fats liquid at room temperature?

their bent chains prevent tight packing

What process creates trans fats?

hydrogenation

Which type of fat is considered the healthiest?

polyunsaturated omega-3 fats

Cholesterol is used to make which of the following?

vitamin D

What is the primary function of phospholipids in the body?

cell membrane structure

Which enzyme begins lipid digestion in the mouth?

lingual lipase

What is the primary function of bile in fat digestion?

emulsifies large lipids into smaller particles

What structure forms when bile mixes with dietary fat?

micelle

Which nutrients enter the brush boarder via micelles?

long-chain fatty acids, cholesterol, fat-soluble vitamins

What lipoprotein is formed inside intestinal absorptive cells?

chylomicron

What enzyme allows cells to take triglycerides from chylomicrons?

lipoprotein lipase

Which lipoprotein delivers lipids from the liver to body cells?

VLDL

Which lipoprotein is formed when VLDL loses triglycerides?

LDL

What is the main function of HDL?

carry cholesterol from cells back to the liver

Which fatty acids bypass lymph and go directly to the liver?

Short‑chain fatty acids

What is the AMDR (Acceptable Macronutrient Distribution Range) for fat for healthy adults?

20–35% of total calories

What is the recommended limit for saturated fat intake?

Less than 7% of total calories

What is the recommended daily limit for cholesterol intake?

300 mg

Which age group has the highest recommended fat intake percentage?

Ages 1–3

What is the recommendation for trans‑fat intake?

Limit as much as possible

Where does fatty acid oxidation occur?

Mitochondria

Fatty acid oxidation requires which of the following?

Oxygen

Fatty acid oxidation provides energy primarily during:

Low‑intensity, long‑duration conditions

What molecule enters the TCA cycle during fatty acid oxidation?

Acetyl-CoA

Which dietary fat pattern helps maintain anti‑inflammatory balance?

Predominantly mono- and poly-unsaturated fats

Which lipoprotein is most strongly associated with increased risk of atherosclerosis?

LDL

Which lipoprotein is considered “protective” against heart disease?

HDL

Which type of dietary fat MOST increases LDL cholesterol?

Saturated fats

Industrial trans fats increase heart disease risk because they:

Raise LDL and lower HDL

Omega‑3 fatty acids are known for which health benefit?

Lowering triglycerides

Atherosclerosis begins with damage to:

The endothelium of blood vessels

Which dietary pattern is most effective for reducing cardiovascular disease risk?

High monounsaturated and polyunsaturated fats

Which condition is strongly linked to high blood triglycerides?

Type 2 diabetes

What is the primary role of HDL in cardiovascular health?

Transport cholesterol to the liver for removal

Which lifestyle factor MOST improves HDL levels?

Regular physical activity

What elements are found in all amino acids?

C, H, O, N

What is the main difference between animal and plant proteins?

Animal proteins are complete proteins

Which food group is highest in phytochemicals and fiber?

Plant proteins

How many amino acids are essential?

9

What makes an amino acid “conditionally essential”?

It becomes essential during illness or metabolic defects

Which condition causes tyrosine to become conditionally essential?

PKU (Phenylketonuria)

What type of bond links amino acids together?

Peptide bond

What determines a protein’s function?

Its three‑dimensional shape

Which example shows how protein shape determines function?

Hemoglobin’s spherical shape helps red blood cells function

What is protein denaturation?

Altering the protein’s 3‑D structure

Where does protein digestion begin?

Stomach

Which stomach enzyme begins protein digestion?

Pepsin

What is the role of hydrochloric acid (HCl) in protein digestion?

Denatures proteins and activates pepsin

Which organ releases enzymes that complete protein digestion?

Pancreas

What is absorbed at the brush border of the small intestine?

Amino acids, dipeptides, tripeptides

What transports amino acids into intestinal cells?

Sodium‑dependent transporters

After absorption, amino acids travel first to the:

Liver

What happens to excess amino acids?

Converted to fat or glucose

What process removes the nitrogen group from amino acids?

Deamination

What toxic by‑product of amino acid metabolism must be converted to urea?

Ammonia

What happens to excess amino acids in the body?

Converted to fat or oxidized for energy

What process removes the amino group (NH₂) from amino acids?

Deamination

Where is urea produced?

Liver

What molecule enters the citric acid cycle after amino acid breakdown?

Acetyl‑CoA

What is the amino acid pool?

Amino acids available from diet and body protein breakdown

What is transcription?

Copying DNA into mRNA

What is translation?

Reading mRNA at the ribosome to build a protein

What happens if an essential amino acid is missing during translation?

The protein cannot be made or body proteins are broken down

Which of the following is NOT a function of proteins in the body?

Long‑term energy storage

What is the AMDR (Acceptable Macronutrient Distribution Range) for protein?

10–35% of total calories

What is the RDA for protein for healthy adults?

0.8 g/kg

How much additional protein is recommended during pregnancy and lactation?

+25 g/day

Which group has the highest protein needs?

Infants

What is positive nitrogen balance?

Making more protein than breaking down

Which situation leads to negative nitrogen balance?

Starvation or severe burns

What defines a high‑quality (complete) protein?

Contains all essential amino acids

Which foods provide complete proteins?

Animal proteins, soy, quinoa

What is protein complementation?

Combining plant proteins to provide all essential amino acids

Which nutrient deficiency is MOST common in vegans?

Vitamin B12

What is Protein‑Energy Malnutrition (PEM)?

A condition caused by insufficient protein and/or energy intake

Kwashiorkor is best described as:

A pure protein deficiency

Marasmus is best described as:

An overall energy deficiency

Food allergies involve:

The immune system reacting to food proteins

Which foods are responsible for most common food allergies?

Milk, eggs, peanuts, tree nuts, wheat, soy, fish, shellfish

Celiac disease is an allergy to:

Gluten

Food intolerance differs from food allergy because:

It does not involve the immune system

Excess protein from animal sources may contribute to:

Cardiovascular disease and Type II diabetes

Excess protein from plant sources is associated with:

No known negative health outcomes

Which PEM condition is associated with a distended abdomen?

Kwashiorkor

When a fatty acid from a triglyceride is used in cellular respiration to generate ATP, the first step of cellular respiration is called:

beta oxidation

The lipid that contributes to blockage of blood vessels (atherosclerosis), which can lead to heart disease.

LDL cholesterol

What lipoprotein transports fats from the diet after they are absorbed in the small intestine?

Chylomicrons

Hydrogenation of unsaturated oils changes the orientation of the fatty acid around the double bond and produces ____________.

trans fat

Most vegetable oils are liquid at room temperature as they are high in: 

unsaturated fatty acids

Which statement regarding dietary fat is true?

Diets high in mono and polyunsaturated fats decrease the risk of heart disease

Cholesterol is only found in foods from animal sources.

True

An unsaturated fatty acid has no carbon-carbon double bonds.

False

Cholesterol is used to make important substances in the body including Vitamin D, hormones, and bile.

True

The 2020-25 Dietary Guidelines recommends limiting _____________ to less than ________ of total calories.

saturated fat; 10%

Humans are not able to synthesize fatty acids with double bonds in the __________ position(s), therefore they are considered essential to get from the diet.

omega-3 and omega-6