A&P II Chapter 24 Mastering A&P Practice Metabolism

The molecule that serves as the major source of readily available fuel for neurons and blood cells is _______

Answer: glucose -fat -glucose -protein -acetyl CoA

__________ are considered "bad" cholesterol; high blood levels are believed to increase the risk of cardiovascular disease.

LDLs LDLs increase the risk for cardiovascular disease.

Lipogenesis occurs when ________.

cellular ATP and glucose levels are high

Glycolysis is best defined as a catabolic reaction based upon the

conversion of glucose into two molecules of pyruvic acid

What is the outcome of ketosis?

metabolic acidosis

It is important to ensure that your diet is adequately rich in vitamins because ________

most vitamins are coenzymes needed to help the body utilize essential nutrients

What process primes a molecule to change in a way that increases its activity, produces motion, or does work?

phosphorylation

The term metabolism is best defined as ________.

the sum of all biochemical reactions in the body

What is the primary function of cellular respiration?

to regenerate ATP Cellular respiration takes energy from our food nutrients and transfers that energy into a usable form of energy in ATP.

Gluconeogenesis is the process in which _______

glucose is formed from noncarbohydrate precursors

__________ refers to reactions in which small molecules are used to build larger molecules.

Anabolism Anabolism refers to the building of macromolecules from smaller precursors (e.g., building proteins from amino acids).

Oxidation reduction reactions ________.

may involve the loss of hydrogen and electrons

The most abundant dietary lipids are _______

triglycerides

Which brain region is the main integrating center for thermoregulation?

hypothalamus The hypothalamus is the main homeostatic integration center for thermoregulation

Which hormone directs essentially all the events of the absorptive state?

insulin

Cholesterol, though it is NOT an energy molecule, has importance in the body because it ________.

is a stabilizing component of the plasma membranes and is the parent molecule of steroid hormones

The process of breaking triglycerides down into glycerol and fatty acids is known as ________.

lipolysis

In the case of a person who consumes a normal, balanced diet, proteins are essential to the body for all of the following EXCEPT ________.

production of energy

Part A - How food fuels cellular respiration Drag the labels onto the flowchart to indicate how food molecules reach the body's cells and fuel cellular respiration. Start with the ingestion of food on the left.

-Eating food provides fuel & building blocks for your body -After food is broken down in the digestive system, it is transport to cells via the circulatory system -Fuel molecules are broken down further in glycolysis & the citric acid cycle (aka krebs cycle) -ATP is produced with the help of the electron transport chain

Part A - Stages of cellular respiration Drag the labels onto the diagram to identify the stages of cellular respiration.

1st- Glycolosis Splitting sugars in cytoplasm, energy investment phase -> 2 ATP molecules combine with glucose molecule. 2nd- Oxidation Pyruvates moving into mitochondria, through oxidation pyruvates broken into water. 3rd- Krebs Cycle/Citric Acid Cycle For every glucose, cycle repeats 2x, breakdown of pyruvic molecules -> carbon dioxide, releases 2 ATP's in this stage 4th- Electron Transport Chain Membrane bound carriers that transports electrons, produces 32 ATP's

Which of the following describes the event depicted on the right side of the figure?

ATP synthesis by oxidative phosphorylation The event at the right depicts how chemiosmosis is used to power ATP synthesis by oxidative phosphorylation.

Which of the following food groups are considered good sources of complete proteins?

Answer: D) eggs, milk, yogurt, meat, and fish A) corn, cottonseed oil, soy oil, and wheat germ B) lima beans, kidney beans, nuts, and cereals C) egg yolk, fish roe, and grains D) eggs, milk, yogurt, meat, and fish

Which of these happens during the postabsorptive state?

Blood glucose levels are maintained within an adequate range. After glucose levels stabilize after a meal, the body tries to maintain the blood sugar until the next meal.

Which of the following is a common feature of both sets of reactions represented by A and B in the figure?

Both include steps involving the oxidation of organic molecules Both glycolysis (A) and the citric acid cycle (B) involve the stepwise breakdown of food molecules by a series of oxidation reactions.

What is the correct general equation for cellular respiration?

C6H12O6 + 6 O2→ 6 CO2 + 6 H2O + ATP energy Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).

There are NO nutritionally complete proteins. All animal products should be eaten with plant material to make a nutritionally complete protein. T/F

False

Part A - Cellular respiration equation Drag the labels onto the equation to identify the inputs and outputs of cellular respiration.

Inputs:1 Glucose (fuel) + 6 O2 Oxygen (gas we inhale) Outputs:6 CO2 (gas we exhale) + 6 H2O (water) + ATP (energy packets that cells use to do work)

Which of the following is the best illustration of the difference between metabolism and digestion?

Metabolism comprises all of the chemical reactions preformed with in the body while digestion is only the breakdown of food within the GI tract.

Which of the following molecules is most directly involved in the transfer of energy from food to the proton pumps depicted in this figure?

NADH Energy released during glycolysis and the Krebs cycle is captured as NAD+ is reduced to NADH. NADH then donates the energy via electrons to the proton pumps

__________ is the energy (kilocalories consumed) that the body uses to perform only its most essential activities.

The basal metabolic rate The basal metabolic rate (BMR) is the energy (kilocalories consumed) that the body uses to perform only its most essential activities, such as breathing and maintaining resting levels of organ function, not all ongoing activities.

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 In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make ATPs

Which statement describes the citric acid cycle?

This process produces some ATP and carbon dioxide in the mitochondrion The citric acid cycle breaks down carbon molecules, releasing carbon dioxide and forming some ATP.

Which statement describes glycolysis?

This process splits glucose in half and produces 2 ATPs for each glucose. In glycolysis, glucose is split into two molecules of pyruvic acid. The released energy is stored in ATP and the electron carrier NADH.

Carbohydrate and fat pools are oxidized directly to produce cellular energy, but amino acid pools must first be converted to a carbohydrate intermediate before being sent through cellular respiration pathways. T/F

True

For use as fuel, all food carbohydrates are eventually transformed to glucose. T/F

True

In order for amino acids to be oxidized for energy, the amine group (NH2) must be removed. T/F

True

GI stretch is a short-term regulator of food intake. T/F

True There are short- and long-term regulators of food intake. Short-term regulators include neural signals from the GI tract (stretch receptor stimulation), blood levels of nutrients (for example, blood levels of fatty acids and amino acids), and gut hormones (such as cholecystokinin). Long-term control of food intake is regulated by the hormone leptin. Leptin is secreted exclusively by adipose cells in response to increased body fat.

Glycogenesis occurs when ATP levels are high and glucose is abundant. T/F

True Glycogenesis is the process of forming glycogen. This occurs when energy levels are high and glucose can be spared.

Glycogen is formed in the liver during the _______

absorptive state

Which of the following nutrients is NOT matched with its use in the body?

answer: carbohydrates:hormones Proteins and lipids both are used to synthesize hormones, but not carbohydrates -lipids: major energy source for skeletal muscle and hepatocytes -proteins: structural materials in the body -vitamins: act as coenzymes -carbohydrates: hormones

Which of the following is NOT an essential role of the liver?

answer: urea disposal Though the liver is involved in creating urea from ammonia and carbon dioxide, it is up to the kidney to eliminate the urea thus formed. -carbohydrate metabolism -protein metabolism -biotransformation functions -urea disposal

Which of the following is NOT a fat-soluble vitamin?

answer: vitamin B Vitamin B and C is a water-soluble vitamin.

Redox reactions __________.

are characterized by one substance's gaining an electron while another substance loses an electron Redox reactions involve the gain or loss of electrons.

Which hormone promotes protein catabolism?

cortisol As one of the "stress" hormones, cortisol is involved in helping cope with turning to protein and fat breakdown in order to spare limited glucose available if one is injured and unable to eat (postabsorptive state).

Which of the following would decrease body temperature?

dilation of cutaneous blood vessels When blood vessels in the skin dilate, heat from blood in the skin is more likely to dissipate into the environment. This would lead to cooling of the body.

Glucose can be obtained from ________.

glycogenolysis

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

glycolysis Glycolysis, the breakdown of glucose into two molecules of pyruvic acid, takes place in the cytosol, outside the mitochondria.

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

glycolysis → acetyl CoA → citric acid cycle → electron transport chain Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.

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

mitochondrion All of the steps of cellular respiration except glycolysis take place in the mitochondrion.

Which of the following statements best describes complete protein?

must contain all the body's amino acid requirements for tissue maintenance and growth

Where do the processes indicated by the letter C occur?

on the inner mitochondria membrane The enzymes that mediate electron transport and oxidative phosphorylation are located in the cristae formed by the inner mitochondrial membrane.

Which of the following mechanisms produces the most ATP during cellular respiration?

oxidative phosphorylation

When proteins undergo deamination, the waste substance found in the urine is mostly________.

urea

Ammonia, which is a byproduct of protein metabolism, is converted to __________ primarily in the __________.

urea; liver Ammonia produced during protein metabolism is converted into urea in the liver.