Chapter 3

The absorptive process that requires the use of energy to transport nutrients is called_____.

active transport

Which of the following statements regarding enzymes is true? - Some enzymes require a coenzyme to be active. - Enzymes are specific to specific chemical reactions. - The shape of the enzyme's active site determines its activity. - All of these statements are true

all of these statements are true

____ is made in the liver, is stored in the gallbladder, and emulsifies fat for digestion

bile

when fat enters the duodenum, the gallbladder secretes____ to break up the large fat globules.

bile

When the lower esophageal sphincter contracts, food ___.

cannot reenter the esophagus from the stomach

The three structural features of the small intestine that increase its surface area are the _____ , the villi, and the microvilli

circular folds

The system that releases hormones that regulate cells' use of nutrients is the __________.

endocrine system

A fourth method is called ______, which involves a vesicle that forms from the enterocyte's cell membrane, engulfing the nutrient and then drawing the nutrient into the cell.

endocytosis

The process in which whole proteins are absorbed intact from the small intestine is called __________.

endocytosis

without the cartilage at the back of the tongue called the _____, food would enter the trachea during swallowing.

epiglottis

the bolus slides down this tube, called the ________, which connects the pharynx to the stomach.

esophagus

Nutrients are absorbed through the lining of the small intestine via a variety of mechanisms. Most nutrients require _______, where a specific carrier protein is utilized, but no energy is required.

facilitated diffusion

Bacteria in the colon produce ___.

Vitamin K

Celiac disease causes ______

damage to the villi

the first section of small intestine, receiving chyme from the stomach, is called the _____

duodenum

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

false

What nutrient must enter the lymphatic system before entering the bloodstream?

fat

Once absorbed, water-soluble nutrients like carbohydrates and amino acids enter capillaries and travel to the liver via the ______

hepatic portal vein

Most water is absorbed in the _____, and solid waste is then eliminated.

large intestine

this large gland, located near the stomach, releases digestive enzymes after a meal and also secretes insulin and glucagon to control blood glucose levels. This accessory organ is called the _____.

pancreas

what organ produces insulin?

pancreas

A process called ______ helps to propel first the bolus and then chyme forward through the esophagus, stomach, and small intestine.

peristalsis

Food is propelled forward by rhythmic contractions called _____, which moves down the esophagus and through the stomach.

peristalsis

the secretions called _____ saliva are produced in the glands located behind the tongue and contain the enzyme amylase to chemically digest carbohydrate.

saliva

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

small intestine

The primary organ for digestion and absorption is the ___.

small intestine

Foods that leave the stomach the fastest are those that are high in ___.

sugar

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

true

Enzymes are proteins, which catalyze chemical reactions.

true

_____ are finger-like projections that cover the circular folds of the small intestine and contribute to its increased surface area

villi

The __ protects the trachea while swallowing.

epiglottis

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

facilitated diffusion

The mixture that leaves the stomach for the small intestine is called __________

chyme

Some smaller molecules can cross via ______. Like with facilitated diffusion, no energy is required because the concentration of a nutrient is higher inside the GI tract than in the enterocyte. Unlike with facilitated diffusion, however, no ______ is needed.

-passive diffusion -carrier protein

Nutrients like glucose and amino acids are absorbed through ______, which requires both a carrier protein and energy in the form of ATP.

active transport

chyme passes through the _____ that connects the ileum with the ascending colon.

ileocecal sphincter

the last portion, or segment, of the small intestine is called the _______

ileum

the _____ is the middle portion of the small intestine.

jejunum

villi contain _____ and _____ blood vessels that absorb nutrients, which are then transported through the body.

lymph vessels and blood vessels

Fat-soluble nutrients initially travel via the ______ before entering the bloodstream.

lymphatic system

during _____, teeth cut and grind food into smaller pieces as the tongue mixes them with saliva.

mastication

the hair-like projections that cover the surface of an intestinal cell and contribute to the increased surface area of the small intestine called ____

microvilli