Nutrition Exam 1: CHAPTER 3

Heartburn

(indigestion, acid reflux). Occurs when LES doesn't close properly, allowing HCl from stomach to flow back into esophagus. Chronic heartburn is typical of gastroesophageal reflux disease (GERD). Certain foods and lifestyle factors are associated with it. Change in diet, antacids, prescription drugs may help.

Enzymes

-are proteins that catalyze hydrolysis to split bonds of all digestible foods and produce molecules small enough to be absorbed by the intestines -aren't changed in the reaction and so can be used over and over again. -are produced in the pancreas, with the last of the digestive enzymes released by the brush border of the small intestine.

Which of the following statement(s) regarding digestion is/are correct?

All of these statements are correct. - The gallbladder secretes bile, which emulsifies the fat, breaking it into smaller particles. - Mechanical digestion in the stomach mixes and churns the bolus until it becomes a liquid called chyme. - The presence of chyme in the duodenum stimulates the gallbladder and the pancreas to release bile and pancreatic juice.

Bicarbonate

Bicarbonate ions alter the pH of chyme, protect the cells lining the duodenum, and provide favorable pH for pancreatic and brush border enzymes

hepatic portal vein

Blood is oxygenated at the lungs and pumped continuously throughout the body During digestion blood travels through the arteries to the capillaries lining the intestinal tract. Here, nutrients cross the intestinal wall to the blood and are transported to the liver

________ causes the pancreas to release lipase and the gallbladder to contract and release bile.

Cholecystokinin

Which of the following statements would be true if a significant length of the small intestine was NOT functioning properly?

Digestion and absorption will be affected.

Small fat-soluble molecules, such as free fatty acids and fat-soluble vitamins, are absorbed through facilitated diffusion in the small intestine.

False

Pepsin can begin the digestion of protein in the stomach after it is converted from pepsinogen by __________.

HCl

Juliana's uncle was diagnosed with gallbladder disease. Eventually he had to have his gallbladder removed. Juliana, a biology major, knew that the gallbladder is necessary for fat digestion and worried about her uncle's long-term health. How does his body digest fat without this accessory organ?

His liver continues to produce bile for fat metabolism, but the bile is secreted directly into the duodenum.

What is the role of a sphincter?

It regulates the directional flow of gastrointestinal contents.

Which of the following statements is true about the gallbladder?

It stores bile and releases it into the small intestine.

Esophageal cancer

Sufferers are typically males over age 50 who live in urban areas and smoke and drink heavily. Treatment can be through surgery, radiation, and chemotherapy.

Bile

Synthesized by the liver, bile helps digest dietary fat, increases the absorption of fat-soluble vitamins, helps neutralize excess HCl, and helps destroy bacteria in food

mastication

The teeth cut and grind food into smaller pieces

Amino acids are absorbed through the process known as active transport.

True

Food that has been moistened with saliva and then swallowed through the esophagus is called __________.

a bolus

endocytosis

a cell forms a vesicle to surround and engulf a nutrient, and the nutrient is dissolved in water inside the vesicle, allowing whole proteins to be absorbed intact.

To form a larger molecule, a condensation reaction occurs when __________.

a hydroxyl group (−OH) from

During hydrolysis, water is used to split apart two glucose molecules by __________.

adding one hydrogen (H) and one hydroxyl (−OH) to each monosaccharide

Gastric inhibitory peptide

also inhibits gastric motility and stomach secretions.

Intestinal gas is a result of

bacterial fermentation.

active transport

both a carrier molecule and energy are necessary to absorb nutrients from low to high concentration.

Bolus

broken-down mass

In facilitated diffusion, what helps nutrients cross the membrane wall?

carrier proteins

Andrea often feels tired. She is losing weight and frequently has an upset stomach. Her joints ache, and lately she has also noticed a rash on her skin. Her digestive symptoms worsen when she eats a meal with bread or pasta. What do you think is most likely to be Andrea's diagnosis?

celiac disease

When the epiglottis does NOT function properly, this condition can cause

choking.

The semiliquid mass that leaves the stomach and enters the small intestine is called __________.

chyme

The chemical process by which glucose is added to a string of glucose molecules to form glycogen in the liver and muscle is called __________.

condensation

Pepsinogen

converted to pepsin by the presence of HCl, beginning the digestion of protein

Bile acts as a(n)

emulsifier.

Hydrochloric acid (HCl)

essential to digestion as it changes the acidity of digestive fluids; can activate proteins and enhances absorption of certain minerals

The absorption mechanism that requires a specific carrier molecule, but no energy, to move digested nutrients across the cell membrane is called __________.

facilitated diffusion

Villi

finger-like projections in the intestinal wall

A muscle located at the end of the esophagus must relax before the bolus can enter the stomach. This muscle is called the __________.

gastroesophageal or lower esophageal sphincter

Rose was so focused on studying for her final exam that she was surprised when her brother knocked on her door and told her that dinner was ready. She smelled the yeast rolls warm from the oven and realized how hungry she was. Which hormone played a role in Rose's physiological response to dinner?

ghrelin

Water-soluble nutrients are carried to the liver from the intestine via which of the following?

hepatic portal vein

Enzymes break apart molecules during digestion by a chemical process known as __________.

hydrolysis

All of the following are segments of the large intestine except the

ileum.

Gastroenteritis

is the inflammation of the stomach or intestines and can be caused by a variety of viruses. Symptoms can include nausea, vomiting, diarrhea, and abdominal cramping, and can usually be cured through rest, oral rehydration therapy, and a diet of soft foods.

The first destination for absorbed nutrients is the __________, transported via the __________.

liver; hepatic portal vein

During the process of digestion, the pH in the stomach is ________ the pH in the small intestine.

lower than

Lipids are transported via the __________ because they are __________.

lymphatic system; fat-soluble

Peristalsis is a form of

mechanical digestion.

Chemical digestion __________.

occurs when enzymes break apart large molecules into smaller molecules

Saliva

produced by the salivary glands functions mostly as a lubricant; helps protect teeth and sanitize the mouth; contains bicarbonate, which neutralizes acids in food (essential for optimal enzyme activity of salivary amylase).

pancreas

produces and secretes digestive enzymes into the small intestine.

Mucus production in the gastrointestinal tract

protects the lining of the GI tract from digestive action.

Proteases

protein-digesting enzymes that attack bonds and hydrolyze them into shorter chains

What are the primary functions of bicarbonate ions in the gastrointestinal tract?

raise pH and neutralize acids

liver

receives absorbed nutrients, plays a role in carbohydrate metabolism, produces proteins, and manufactures bile salts used in fat digestion. The liver is the largest internal organ in the body.

gallbladder

receives bile from the liver, concentrates it, and secretes the bile into the small intestine.

A key difference between active transport and diffusion is that active transport __________.

requires ATP

Segmentation

shifts food along the intestinal wall. Segmentation moves food along the intestinal walls to increase surface contact with the small intestine. Segmentation in the large intestine is much slower to allow for the maximum amount of water absorption.

Most nutrient absorption takes place in the __________.

small intestine

The absorption of the majority of ingested nutrients takes place largely in the __________.

small intestine

Where do both peristalsis and segmentation occur?

small intestine

The ileocecal valve connects

small intestine to large intestine.

facilitated diffusion

some nutrients, such as fructose, require specific carrier proteins for absorption. a. The process does not require energy, and transport is from high to low concentration.

Peristalsis

squeezes food forward. The circular, longitudinal, and diagonal muscles are important in coordinating rhythmic motion to accomplish the task of propelling food forward in the GI tract. By the time the food leaves the stomach, liquid chyme is created.

The substance or compound that an enzyme has specificity for is called the

substrate.

Treatment for constipation includes all of the following except

taking antibiotics.

colon

the largest part of the large intestine. The rectum and anus are the final parts of the large intestine.

All of the following statements are true about the liver except

the liver stores bile and releases it to the small intestine.

Digestion

the process in which chemicals and mechanical processes break the bonds and reduce food into individual molecules.

Passive diffusion

the simplest process, absorbs nutrients based on varying concentration gradients. a. If concentration of a nutrient is greater in the GI tract than in the enterocyte, the nutrient is forced across the cell membrane, moving from high to low concentration. b. Neither energy nor a special carrier molecule is necessary for this process. c. Water, some lipids, some minerals, and vitamin C are absorbed via passive diffusion.

cholecystokinin (CCK)

this hormone stimulates the pancreas to release lipase and the gallbladder to release bile, while it slows down gastric motility and contributes to meal satisfaction.

The fingerlike projections on the small intestine that increase its surface area are called __________.

villi

What is primarily absorbed in the large intestine?

water and electrolytes

ghrelin and peptide YY

work together with the extrinsic and intrinsic nerves to communicate feelings of hunger or fullness. Ghrelin is released from the gastric cells when the stomach is empty, while peptide YY signals the brain when the stomach is full.