Physiology 23

Glycolysis breaks down glucose into what?

pyruvate

What happens to the ammonium ions that are removed from amino acids during deamination?

they combine with CO2 and enter the urea cycle

Which energy-rich molecule produced by cellular respiration directly powers cell work?

ATP

How do the absorptive and postabsorptive states maintain normal blood glucose levels?

During the absorptive state, insulin stimulates glucose uptake by cells and during the postabsorptive state, glucagon stimulates the breakdown of glycogen to form glucose.

Which statement describes the electron transport chain?

This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.

If Keith adopts an all-meat diet, with which vitamin below should he make sure to supplement his diet to avoid deficiency?

Vitamin A

Explain when glycolysis is important in cellular metabolism.

When ATP must be produced anaerobically.

Explain the process of metabolic turnover.

When cells continuously replace cellular components.

Which step of glucose metabolism yields the greater amount of ATP?

electron transport system

What is the most important product of the reactions of the citric acid cycle, which will allow the mitochondria to produce ATP?

energy-rich hydrogen atoms

The cholesterol determination is _______.

enzymatic and colorimetric

Linoleic acid and linolenic acid are examples of

essential fatty acids

Fatty acids that are necessary for proper health but cannot be synthesized by the body are called

essential fatty acids.

In the postabsorptive state of metabolic activity, __________.

glucocorticoids stimulate the mobilization of lipid and protein reserves

Which process describes the synthesis of glucose from noncarbohydrate sources?

gluconeogenesis

All of the following are reasons why glucose is the primary energy source for cells

glucose can be stored efficiently. glycolysis does not require oxygen to generate ATP. glycogen breakdown involves only a single enzymatic step. glucose is a small, soluble molecule.

Which of the following processes takes place in the cytosol of a eukaryotic cell?

glycolysis

Where does most nutrient absorption occur?

in the small intestine, primarily in the jejunum

Which of the following body systems is not involved in capturing or creating energy that is used to maintain one's metabolism?

integumentary

The major job of coenzymes in oxidative phosphorylation includes all of the following

ionization of hydrogen atoms. release of electrons to the first cytochrome of the electron transport chain. release of hydrogen ions.

All of the following are true of beta-oxidation

it ultimately yields large amounts of ATP. fatty acids break down into acetyl-CoA that enter the citric acid cycle. it requires coenzyme A, NAD, and FAD. it occurs in the mitochondria.

Cells perform catabolism to generate ATP, which can be used for all of the following

protein synthesis. ion transport. diffusion. muscle contraction. glycogen synthesis.

sequence of steps as energy is extracted from glucose during cellular respiration.

glycolysis → acetyl CoA → citric acid cycle → electron transport chain

A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as

gout.

Most of the absorbed nutrients enter into which blood vessel?

hepatic portal vein

Which of the following were disposed of in the biohazardous waste disposal?

the alcohol wipe, the lancet, and the cholesterol strip

Which of the following contains the most energy that can be used to make ATP?

1 gram of fat

List the products of glycolysis.

2 molecules of pyruvate, 2 molecules of ATP, 2 molecules of NADH

Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual.

20

correct general equation for cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy

Compare catabolism and anabolism.

Catabolism is the breakdown of large molecules into smaller ones, whereas anabolism is buildup of large molecules from smaller building blocks.

Identify the fates of fatty acids

Fatty acids may become a fuel source or a component of triglycerides, glycolipids, phospholipids, prostaglandins, cholesterol, and steroids.

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

Glucose

Compare glycogenesis and glycogenolysis.

Glycogenesis is the formation of glycogen from glucose. Glycogenolysis is the breakdown of glycogen to glucose.

Why is glucose the primary energy source for cells?

It can be efficiently stored as glycogen, which forms compact, insoluble granules

Explain the role of glycogen in cellular metabolism.

It serves as an intracellular glucose reserve.

Keith is concerned that his brain cells will not receive energy-rich nutrients without carbohydrates in his diet. Which of the following molecules is a product of lipid catabolism that his brain cells could use to create ATP?

Ketone bodies

Describe the roles of LDLs and HDLs

LDLs deliver cholesterol to tissues and HDLs absorb unused cholesterol and return it to the liver.

Describe leptin and its effect on appetite.

Leptin is a peptide hormone produced by adipose tissues during the synthesis of triglycerides and it signals satiety.

Which of the statements below represents one potential disadvantage to Keith's proposed all-meat diet?

Lipid catabolism is slower than carbohydrate catabolism

What is the difference between a micelle and a chylomicron?

Micelles are lipid-bile salt complexes, whereas chylomicrons are lipoproteins.

Based on the general theme of conservation, which of the following is most likely to happen if an athlete breaks his arm and must wear a cast and not use that arm for six weeks?

Muscles in the injured arm will get smaller because they are not being used.

What two coenzymes transfer hydrogen atoms to the electron transport chain?

NAD and FAD

What is the primary way energy is shuttled from the citric acid cycle to the electron transport system?

NADH

Compare oxidation and reduction.

Oxidation is the gain of oxygen, or loss of hydrogen or electrons, whereas reduction is the loss of oxygen, or the gain of hydrogen or electrons

Briefly describe phenylketonuria (PKU).

PKU is an inherited metabolic disorder resulting from an inability to convert phenylalanine to tyrosine.

Explain why carbohydrates are preferred over proteins and lipids as an energy source.

Proteins and lipids are more important as structural components of cells and tissues.

Which is true regarding lipoproteins and lipid transport and distribution?

The HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile

Describe the role that hydrogen ion channels play in the generation of ATP

They allow hydrogen ions to diffuse from the intermembrane space into the matrix to power ATP synthase.

Glucocorticoids have which of the following effects on general peripheral tissues?

They increase glycogenolysis. They increase gluconeogenesis. They increase the conversion of amino acids to pyruvate.

describes the citric acid cycle?

This process produces some ATP and carbon dioxide in the mitochondrion.

Which 2-carbon molecule is inserted into the reactions of the citric acid cycle to start these reactions?

acetate

What molecule forms the common substrate for the citric acid cycle?

acetate ion

Growth and repair involve primarily what type of reactions?

anabolic

In the absorptive state of metabolic activity:

androgens, estrogens, and growth hormone stimulate protein synthesis.

Describe the source of intestinal gas.

bacterial metabolism of indigestible carbohydrates in the colon

The process that catalyzes fatty acids using enzymes that generate acetyl-CoA is called

beta-oxidation.

When your muscles contract to move your body, such as during walking, work is done, and work requires energy. Based on the Law of Conservation of Energy, from where does this energy come?

chemical energy

LDLs contain _______.

cholesterol and protein

The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the

chylomicrons.

Poisons like cyanide bind to ________ and prevent electron transfer.

cytochromes

Which of the following occurs when water is released (lost) during a reaction?

dehydration synthesis

When and how do ketone bodies form?

during the postabsorptive state when lipids and amino acids are broken down by the live

Urea is formed in the

liver.

Hypocholesterolemia is linked to _______.

low levels of serotonin

Wally decides to go on a hunger strike to further one of his favorite causes. After many days with nothing but water you would expect to observe

lowered blood pH. ketone bodies in his urine. elevated levels of glucocorticoids.

The sum of all of the biochemical processes going on within the human body at any given time is called

metabolism.

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?

mitochondrion

How are most nutrients absorbed in the digestive tract eventually transported out of the digestive system?

through the hepatic portal vein

In amino acid metabolism, identify the processes by which the amino group is removed.

transamination or deamination

describes glycolysis?

This process splits glucose in half and produces 2 ATPs for each glucose.

Which of the following is not a product of cellular respiration? water (H2O) carbon dioxide (CO2) ATP oxygen (O2)

oxygen (O2)

When chyme arrives in the duodenum, cholecystokinin (CCK) release triggers the secretion of which enzyme?

pancreatic alpha-amylase

All of the following is true of the electron transport system

produces energy that supports the synthesis of ATP. receives electrons from coenzymes. electrons are eventually accepted by oxygen with the formation of water. is found on the inner mitochondrial membrane (the cristae).