NUTRITION SCIENCE EXAM 2

monosaccharide

a sugar that does not hydrolyze to give other sugars, the simplest group of carbohydrates
-Glucose, fructose, and galactose

Which monosaccharides make up sucrose, maltose, and lactose?

sucrose= one glucose + one fructose
Maltose= glucose + glucose
lactose= glucose + galactose

Disaccharides

Two molecule sugars
-Lactose, Maltose, sucrose

Kcal Sugar vs. Honey

honey has more calories that sugars

oligosaccharide

Carbohydrates that contain 3-10 monosaccharides.
-Raffinose and Stachyose

polysaccharides

Hundreds of thousands of glucose molecules
-Starch, Glycogen and fibers

fiber

Fiber is long polysaccharide chains.
Soluble fiber --> beans, Brussel sprouts, avocado
insoluble fiber--> wheat bran, veggies, whole grains

soluble vs insoluble fiber

soluble= can be dissolved in water
insoluble= can't be dissolved in water

secretions in mouth that aide in digestion of Carbs?

salivary amylase

fiber rich carbohydrates

fruits, vegetables, whole grains, and legumes

insulin

hormone secreted by the pancreas; regulates storage of glycogen in the liver and accelerates oxidation of sugar in cells

glycemic index

the potential of food to raise blood glucose levels

Adequate intake fiber for men

30-38 grams per day

Adequate intake of fiber for women

21-25 grams per day

benefits of increasing your fiber

reduce constipation

reduce risk of disease

heart disease and obesity

What do cells use for energy?

Cells use carbohydrates for energy but can also use lipids. In some cases, proteins.

What happens to glucose not used immediately for energy?

It is stored as fat.

A diet high in sugar may cause?

Diabetes-- when the body does not produce insulin.

What are Sugar Alcohols? What products are they found in?

A type of carb that contains sugar and alcohol groups.
Found in fruits and vegetables.

Type 1 Diabetes vs. Type Two Diabetes

Type one-- the body cannot produce enough insulin.
Type Two—cells don’t respond to the insulin and lots of glucose remains in the blood stream.

lactose intolerance

congenital disorder consisting of an inability to digest milk and milk products; absence or deficiency of lactase results in an inability to hydrolyze lactose

Where does chemical digestion of carbs begin?

In the mouth

What are amylases?

An enzyme that converts starch and glycogen into simple sugars.

Where is fructose transported to? What is fructose converted into?

Fructose joins together with galactose and glucose to form various disaccharides.

Which lipid is found most abundantly in food?

Triglyceride

How are fats helpful to the human body?

Source of essential fatty acids, help body absorb fat soluble vitamins

Risk factors for heart disease

high blood pressure, diabetes, obesity, physical inactivity

Know the recommended blood cholesterol levels according to the National Heart, Lung, and Blood Institute.

Less than 200 mg/dL= desirable

200-239= borderline high

240+= high

What is ketosis and what type of diet would cause it?

Important mechanism for providing energy to brain during sleep and exercise

Diet of low carbs

What are the 3 classes of lipids? Discuss functions of each.

Triglycerides- long term energy source

Phospholipids- structural component of cell membranes

Steroids- hormone in plants and animals, structural component of cholesterol

What type of lipid is most common, both in the food we eat and how we store fat?

triglycerides

How are triglycerides classified?

Simple or mixed based on fatty acid that’s present in molecule

Define saturated, monounsaturated, polyunsaturated fats. Give examples of foods which have each.

Saturated- dietary fat, unhealthy, foods are solid at room temp (butter, palm and coconut oil)

Monounsaturated- fat in fatty acid molecules, contain one unsaturated double bond, melting point is less than compared to saturated, liquid at room temp (nuts, oils, avocados, and fish)

Polyunsaturated- dietary fat, healthy, (salmon, veggie oils, and nuts and seeds)

What are trans fatty acids? What do they do?

Worst type of fat to eat, raise “bad” cholesterol and lowers “good”

Increases risk for heart disease

What indicates a food contains trans fats?

Partially hydrogenated oils

Examples of omega-3 fatty acids. Why are they beneficial?

Fish, veggie oils, nuts, flax seeds, leafy veggies

Integral part of cell membranes throughout body and affect function of cell receptors

What are sterols? How are they beneficial to us?

Group of naturally occurring unsaturated steroid alcohols widely distributed in animals and plant lipids

Can lower blood cholesterol concentrations, and body needs a certain amount to function

Where is Alpha-linolenic acid found?

Found in plants (flaxseed, canola, and soy oil)

Where does our body store fat for later energy use?

Stores energy as glycogen or fat, these compounds stored in liver, or muscle/fat cells

How does eating a very low fat diet affect vitamin absorption?

Some vitamins are fat-soluble so they can only be absorbed when consumed with fat, so they will not be absorbed as well

Where does the majority of fat digestion and absorption occur?

Small intestine

What affects our cholesterol levels in our blood?

Smoking, diet, exercise levels, diabetes, and high blood pressure

Following a healthy pattern or eating, cholesterol intake should be how many mg/day?

No more than 200

How are proteins helpful to the human body?

help body repair and make new cells, building block for bones, muscles, cartilage and skin

How are amino acids distinguished from one another? What differences does that make?

By R groups- side chains

They differ in structure, electrical charge and polarity

Know the essential amino acids.

Histidine, isoleucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine

What are nonessential amino acids?

Alanine, arginine, asparagine, cysteine, glutamine, glycine, proline, serine, and tyrosine

What is the difference between transamination and deamination?

Transamination- transfer of an amine group from one amino acid to another and is used to synthesis nonessential amino acids

Deamination- removal of an amine group as ammonia

What is the by-product of deamination? When does deamination occur?

Ammonia

When an excess in protein is consumed

How are 2 amino acids joined together? What byproduct is formed?

Linked by peptide bonds

water is formed

What breaks down polypeptides in the small intestine?

Proteases

Pancreas secretes digestive juices that contain these

What is a complete protein?

Food source of protein that contains and adequate proportion of each nine essential amino acids

What are proteases?

Enzymes that aid in the breakdown of proteins.

How are proteins denatured?

When normal shape gets deformed cause hydrogen bonds are broken

Where does chemical digestion of protein begin?

The small intestine

What is the PDCAAS score? What foods will have higher and lower scores?

Methods of evaluating quality of a protein based on amino acid requirements of humans and ability to digest it

High- is milk protein

Low- beans, legumes, eggs

What is PKU?

Phenylketonuria is a genetic disorder that prevent the breakdown of the amino acid phenylalanine.

Vegetarian classifications…what do they eat? What are complementary proteins?

Fruits, veggies, grains, fats, and proteins

Complementary- plant based proteins that when eaten together provide essential amino acids making a complete protein

What nutrients are of most concern for vegetarians?

Vitamin B and D, calcium, iron, fatty acids, zinc

Differences between marasmus and kwashiorkor?

Kwashiorkor- severs protein deficiency

Marasmus- sever calorie deficiency

What does research suggest about high protein diets?

They leave you feeling fuller longer, causing a person to eat less calories.

How do you correct PEM?

Increase intake of protein containing foods- nuts, eggs, seafoods, poultry

What are examples of diseases associated with genetic abnormalities?

down syndrome, cleft lip

What is Nitrogen Balance? When might a person be in positive or negative nitrogen balance?

A method used to determine protein needs.

Positive balance people who consume more nitrogen than excreted.

Negative balance people excrete more nitrogen than is consumed.

Be able to calculate protein needs for an individual (sedentary vs athlete)

Sedentary- .8* weight in kilograms

Athlete- 1.2-2.0* weight in kilograms