Nutrition Final Exam Davis TCU

Energy yielding nutrients

Lipids, fats, and proteins

The amount of energy released is measured in ____

Kilocalories

What do energy yielding nutrients assist with?

They are used to fuel all activities in the body

Where do excess energy yielding nutrients go?

Storage in glycogen/fat

Acceptable carbohydrate distribution range

45-65% of calories

Acceptable fat distribution range

20-35% calories

Acceptable protein distribution range

10-35% calories

How many calories per gram are in carbohydrates?

4 calories per gram

How many calories per gram are in fats?

9 calories per gram

How many calories per gram are in proteins?

4 calories per gram

How many calories per gram are in alcohol?

7 calories per gram

Organic nutrients

Organic, contain carbon and not all provide energy

Carbohydrates, proteins, lipids, and vitamins

What are the organic nutrients?

Carbohydrates, proteins, lipids, and vitamins

Vitamins

Do not provide energy

Essential organic nutrients required in small amounts

Serve as helpers in metabolic processes and may be subtly altered to perform various tasks

May be water soluble

May be fat soluble

Inorganic nutrients

Do not provide calories

Do not have carbon

Minerals, and water

What are the inorganic nutrients?

Minerals, and water

Minerals

Inorganic molecules required in small amounts

Do not provide energy

Elements that cannot lose their identity

May bind with certain substances and don't get absorbed by the body- binding with phytates/oxalates

DRI (dietary recommended intakes)

A set of values for the dietary nutrient intakes of healthy people

RDA (recommended daily allowance)

The average amount of a nutrient considered adequate to meet the needs of all healthy people

EAR (estimated average requirements)

The amount of a nutrient that will maintain a specific biochemical or physiological function in ½ the people of a given age and gender group

AI (adequate intakes)

The average amount of a nutrient that appears sufficient to maintain health

TUIL (tolerable upper intake levels)

The maximum amount of a nutrient that appears safe and beyond which there is a risk of adverse health effects

Enriched foods

An addition to a food of specific nutrients to replace losses that occur during processing so that the food will meet a specific standard

Fortified foods

Addition to a food of nutrients that were either not originally present or present in insignificant amounts

Ingredient list

Listing of all ingredients

Descending order of predominance by weight

Serving sizes

Food and Drug Administration (FDA) role

Adjust calculation according to amounts consumed

Sized listed vs. USDA food pattern sizes

Nutrition facts- required information

Total food energy and energy from fat

Total fat, saturated fat, trans fat, & cholesterol

Sodium

Total carbohydrates, dietary fibers, & sugars

Protein

Vitamin A&C, iron, and calcium

Daily values

Expressed as percentage

Relationship to health

"Ballpark" estimate of contribution to total diet

Based on 2,000 calories per day

Percent daily value

Percentage of a daily value recommendation found in a specified serving of food for key nutrients based on a 2,000 calorie diet

≥ 20%= high or excellent source

10-19%= good source

≤ 5%= low source

≥ 20% of the daily value

High or excellent source of the daily value

10-19% of the daily value

Good source of the daily value

≤ 5% of the daily value

Low source of the daily value

Gastrointestinal tract (GI tract)

Flexible muscular tube from the mouth→esophagus→stomach→small intestine→large intestine→rectum→anus

Principal organs of absorption and digestion

Stomach

Intestine

Lumen

Inner space within the GI tract

Mouth

Oral cavity includes lips, teeth, tongue, and palate

Begins digestive process- motility and secretion

Salivary glands- secrete saliva

Contains digestive enzymes for starch (salivary amylase)

4 basic taste sensations: sweet, sour, bitter, salty, and savory (umami)

Tongue- taste sensations and food movement

Bolus

The amount of food swallowed at one time

Pharynx

A short tube shared by both digestive system and respiratory system

Epiglottis

Protects the airway during swallowing

First regulation of intake

Esophagus

Food pipe- passes food from mouth→ stomach

Primary function= motility

Passes through a hole in the diaphragm

Upper esophageal sphincter

Opens during swallow

Cardiac or lower esophageal sphincter

Prevents reflux (backflow of content)

Acid reflux

Wear loose fitting clothing, don't eat right before going to bed, sit up when eating and digesting, smaller sized meals, low fat meals- high fat foods loosen up the sphincter and reflux moves up, separate liquids and solids, avoid spicy foods and acidic foods (they don't loosen up the sphincter, but if the acid moves up it is painful)

Sphincter

A circular muscle surrounding and able to close a body opening

Stomach

Retains bolus in the upper portion & transfers to lower portion little by little

Adds acid, enzymes, fluid to bolus- bolus becomes chyme

Chyme is released to the small intestine through the pyloric sphincter

Chyme

A semiliquid mass of partly digested food expelled by the stomach into the duodenum

Small intestine

Common bile duct opens into the small intestine

It allows secretions from the pancreas and gallbladder to release into the small intestine

Major site of nutrition absorption and digestion

3 components of the small intestine

Duodenum

Jejunum

Ileum

Pancreatic duct

Conducts pancreatic juice (enzymes/bicarbonate) from the pancreas to the small intestine

What does the pancreas release?

Bicarbonate to neutralize the acid and we can absorb better

Large intestine

Colon

Ileocecal valve- separates the small and large intestine

Reabsorbs water & minerals

Withdraws water from chyme and leaves semi-solid waste

Passes waste & unabsorbed nutrients like fiber on to the rectum for elimination

Transverse colon

As it turns and crosses the body towards the spleen

Descending colon

Turns downward and becomes the sigmoid colon

Sigmoid colon

Extends to the rectum

Rectum

Muscular terminal part of the intestine, extending from the sigmoid colon to the anus

Anus

Final sphincter muscle and terminal outlet of the GI tract to pass stool (feces) out of the body

Ileocecal valve

Separates the small and large intestine

HCL

Secreted in the stomach and breaks down proteins

Helps with the absorption of calcium, iron, and B12

Bicarbonate

Secreted by the pancreas and neutralizes acidic chyme

Where does most digestion occur?

Small intestine

Where does most absorption occur?

Small intestine

Gland

A cell/group of cells that secrete materials

Exocrine gland

Secretes materials out of the body into the digestive tract or onto the skin

What materials do exocrine glands excrete?

Enzymes

Endocrine gland

Secretes materials inside the body into the blood

What materials do endocrine glands excrete?

Hormones

What 5 organs are involved in secretions?

Salivary glands

Stomach

Pancreas

Liver (through the gallbladder)

Small intestine

Pancreatic juices and intestinal enzymes

Released through ducts into the duodenum

Enzymes act on all three energy nutrients- carbohydrates, lipids, and proteins

Bile

Emulsifier bringing fats into suspension with water

Produced by the liver

Stored in the gallbladder

Salivary glands

Target organ is the mouth

Secretes saliva

Fluid eases swallowing, ____ enzymes breaks down some carbohydrates

Gastric glands

Target organ is the stomach

Secretes gastric juice

Fluid mixes with bolus

Hydrochloric acid uncoils proteins

Enzymes break down proteins

Mucus protects stomach cells

Liver

Target organ is the gallbladder

Secretes bile

Bile is stored until needed

Gallbladder

Target organ is the small intestine

Secretes bile

Bile emulsifies fat so that enzymes can have access to break it down

Intestinal glands

Target organ is the small intestine

Secretes intestinal juice

Intestinal enzymes break down carbohydrate, fat, and protein fragments

Mucus protects the intestinal wall

Secretin

A hormone

Responds to acidic chyme in the small intestine

Secreted from the duodenal wall

Stimulates the pancreas

Responds by: bicarbonate-rich juices are secreted into the small intestine to maintain a slightly alkaline pH

It is sensitive to food in the small intestine- sends a message out to the pancreas to send bicarb to neutralize food

Gastrin

A hormone

Responds to food in the stomach

Secreted from the stomach wall

Stimulates the stomach glands

Responds by: hydrochloric acid secreted into the stomach to maintain an acidic pH

Signals for the HCl to be secreted in the stomach

Cholecystokinin (CCK)

A hormone

Responds to fat or protein in the small intestine

Secreted from the intestinal wall

Stimulates the gallbladder and pancreas

Responds by: bile is secreted into the duodenum to emulsify fats; bicarbonate and enzyme-rich juices are secreted into the small intestine to maintain a slightly alkaline pH, it digests fats and proteins, and slows the GI tract motility

Which route are carbohydrates absorbed?

Carbohydrates end at the small intestine and go to the bloodstream from the portal vein to the liver

Which route are small lipids absorbed?

Lipids end at the small intestine and go to the portal vein to the liver

Which route are large lipids absorbed?

Lipids end at the small intestine and go to the lymph

Which route are proteins absorbed?

Proteins end at the small intestine and go to the bloodstream from the portal vein to the liver

Monosaccharides

Carbohydrate

Contains one saccharide molecule

Fructose

Monosaccharide

Sweetest sugar

Fruit sugar

Pentagon shape

Glucose

Monosaccharide

Also called dextrose

Not as sweet

Measured in blood as blood sugar or _____

Galactose

Monosaccharide

Seldom free in nature

Part of lactose (milk sugar)

Disaccharides

Carbohydrate

Consists of a pair of monosaccharides

Sucrose

Disaccharide

Glucose & fructose

Table sugar, also occurs naturally especially in fruit

Lactose

Disaccharide

Glucose & galactose

30-50% of milk energy

Maltose

Disaccharide

Glucose & glucose

Malt sugar, used in the germination of seeds & barley

Polysaccharides/ complex carbohydrates

Composed mainly of glucose units

Should contribute 45-60% of caloric intake

Starch

Glycogen

Starch

Polysaccharide (many monosaccharides)

Serves as a storage form of glucose in plants

Plant polysaccharide composed of glucose

Storage form of glucose in plants

Grains, root crops, tubers, & legumes

Long branched or unbranched chains of hundreds of thousands of glucose molecules

Major source of food energy worldwide

Richest food source is grains

Glycogen

A storage form of glucose in animals

Made and stored in the liver and muscles

More complex and branched than starch

Enzymes can attack all branches simultaneously

Occurs through a condensation reaction

Sources of disaccharides

Kool aid, sugar, coke, dairy, desserts, candy

Sources of polysaccharides

Bread, pasta, cereal grains, potatoes, whole grains, fruits, and vegetables

Fiber

Polysaccharides that are not digested by human digestive enzymes

Bonds between glucose units are unable to be broken

Energy contribution is neglidgeable

Rapid increase may cause discomfort

Increase water intake along with increased fiber

Too much is not better than too little

_______ in foods is preferable to supplements

Dietary fiber

Remains from food after passage through the small intestine prior to bacterial digestion in the colon through fermentation

Everything except lignins and cellulose are digestible

Structural part of plants

Different from starches

Viscous/ soluble

Insoluble

Phytic acid

Viscous/soluble fiber

Decreases cholesterol- binds bile acids

Decreases the rate of glucose absorption

Used to treat diarrhea

Fruit, oats, barley, & legumes

Insoluble fiber

Decreases transit time in the small intestine

Prevents some cancers

Must be used moderately by people with marginal intakes

Vegetables, wheat, & grains

Phytic acid

Found in fibrous foods

Husks of grains, legumes, & seeds

Binds minerals such as zinc, iron, calcium, magnesium, and copper

Cellulose

Fiber

Composed of plant cell walls

Composed of glucose molecules

Hemicelluloses

Fiber

Main constituent of cereal fibers