Human physiology exam 5

The sodium-potassium pump is a trans-membrane protein.

True

Whenever a molecule is oxidized, another molecule must be reduced.

True

The NADH and the hydrogen ions produced in glycolysis must become __________ in the cytoplasm by donating its electrons to pyruvic acid.

oxidized

Cells obtain energy by ________ food molecules such as glucose.

oxidizing

During glycolysis, a 6-carbon sugar diphosphate molecule is split into two 3-carbon sugar phosphate molecules.

true

NADH serves as an electron carrier that can donate its hydrogen to other molecules.

true

The Krebs cycle occurs in the mitochondrion.

true

The binding and release of sodium or potassium ions are due to conformational changes in the protein.

true

Metabolism= All of the reactions in the body that involve energy transformation: two categories anabolism and catobolism. Catabolic reactions= Anabolic reactions=

release of energy by the breakdown of larger organic molecules into smaller molecules. Ex. the breakdown of glycogen into glucose. require the input of energy and include the synthesis of large energy-storage molecules, including glycogen, fat, and protein.

ATP synthase

the enzyme that catalyzes the addition of a phosphate group to adenine diphosphate

The steps of oxidative phosphorylation:

(1) Molecules of the electron-transport system function to pump H+ from the matrix to the intermembrane space. (2) This results is a steep H+ gradient between the intermembrane space and the cytoplasm of the cell. (3) The diffusion of H+ through ATP synthase results in the production of ATP.

3 steps for aerobic cell respiration of glucose:

(1) glycolysis (a metabolic pathway that takes place in the cytoplasm) (2) the citric acid cycle (a metabolic pathway that occurs in the mitochondrial matrix) (3) electron transport (a process that occurs in the mitochondrial cristae).

A healthy young adult undergoes routing blood work for his annual physical. His physician calls with concern about his nitrogen levels, which is abnormally high. Assuming there is no kidney disease present, what might explain this finding?

-A diet that is over 60% protein -A very low calorie diet -A condition that causes an abnormally elevated metabolic rate

Check all that apply as characteristics of brown adipose tissue.

-A major site of thermogenesis by inhibiting the production of ATP, so more fats are hydrolyzed to produce ATP -Abundant in newborns -Produces a unique uncoupling protein -Mostly found in the supraclavicular area

An individual who was previously sedentary decides to train for a 5-mile race. Over the course of several weeks, his running feels much easier and he is able to run for longer periods of time before experiencing fatigue. Which of the following cellular adaptations can explain his improvement?

-Decreased lactic acid production in skeletal muscle -Increased levels of enzymes needed for aerobic cellular respiration -Increased mitochondria in adipose cells

A single "turn" of the Krebs cycle will yield

1 ATP, 3 NADH, and 1 FADH2.

The NET result of a single glycolysis run is the formation of

2 NADH and 2 ATP.

The initial reaction of the Krebs cycle involves the addition of a

2-carbon molecule to a 4-carbon molecule.

During one cycle, the sodium-potassium pump binds and moves.

3 Na+ and 2 K+.

The actual ATP yield, after allowing for the costs of transport into the cytoplasm, is approximately ________.

30 to 32 ATPs

During the citric acid cycle, one molecule of FAD is reduced to __________.

FADH2

Which of the following best describes the reduction of the coenzyme NAD?

NAD+ + H -> NADH

Anaerobic metabolism=

The metabolic pathway by which glucose is converted into lactic acid without oxygen used.

Aerobic respiration is affected when cells have all the ATP they need by glucose converted to fat, glucose converted to glycogen, and ATP production is inhibited. Aerobic respiration uses lipids, glucose, and proteins to produce ATP. It is the metabolic pathway that uses oxygen to convert molecules such as glucose or fatty acid to CO2 and water (transferring some of the energy to ATP) The oxygen for this process is obtained from the blood which obtains oxygen from air in the lungs through the process of breathing or ventilation. Ventilation eliminates the carbon dioxide produced by aerobic cell respiration. In aerobic respiration, the energy is released in small, enzymatically controlled oxidation reactions, and 38% to 40% of the energy released is captured in the high-energy bonds of ATP. In aerobic respiration, pyruvic acid leaves the cell cytoplasm and enters the interior (the matrix) of mitochondria.

The oxygen for this process is obtained from the blood which obtains oxygen from air in the lungs through the process of breathing or ventilation. Ventilation also serves the important function of eliminating the carbon dioxide produced by aerobic cell respiration.

A hydrogen atom consists of

a proton and an electron.

Before entering the Krebs cycle, pyruvate is converted to

acetyl-CoA

Metabolism may be divided into 2 categories: ____________ and catabolism. ____________ reactions release energy, usually by the breakdown of larger ____________ molecules into smaller molecules. ________ reactions require the input of energy and include the synthesis of large energy-storage molecules. Energy transfers are less than ____________ efficient according to the ____________ Law of Thermodynamics. Some of the ____________ -bond energy from glucose is ____________ as heat.

anabolism catabolic organic anabolic 100% 2nd chemical lost

The process by which fatty acids from triglycerides are converted to acetyl coenzyme A is called __________.

beta-oxidation

The __________ uses blood glucose as its major source of energy.

brain

What is the source of energy used to power the sodium-potassium pump?

breakdown of ATP

According to the ___theory, the electron-transport system (ETS) pumps ____ from the matrix into the space between the inner and outer mitochondrial membrane. This system is powered by the transport of ____. The ETS is grouped into ___ complexes that serve as ____pumps The ____ complex transports 4 H₊ from the matrix to the intermembrane space. The ____ complex also transports __protons into the intermembrane space. The cytochrome c oxidase complex transports ___protons into the space. In the last step of the ETS, ____is the final electron acceptor. Mitochondrial DNA codes for 13 of these proteins, and nuclear DNA codes for the rest.

chemeostatic protons electrons 3 proton NADH-enzyme Q reductase cytochrome c reductase 4 2 O2

A single "turn" of the Krebs cycle involves three different decarboxylation reactions.

false

Under aerobic conditions, the end-product of glycolysis is further reduced to yield more ATP.

false

The formation of glucose from amino acids is called ____. The process by which amino acids are converted to urea is called _____. More importantly, all organs must use ____________ primarily for energy. After anaerobic exercise, lactic acid is converted to pyruvic acid, which enters the ____________ pathway and can be used for energy. The main substrates for gluconeogenesis are the three-carbon-long molecules of alanine, glycerol, and ____________ . Keto acids can be converted to amino acids by the process of ____________ .

gluconeogenesis. oxidative deanimation glucose aerobic lactic acid transanimation

Glycogenesis.

is The formation of glycogen from glucose. Glucose is converted to glucose 6-phosphate by utilizing the terminal phosphate group of ATP. Glucose 6-phosphate is then converted into its isomer, glucose 1-phosphate. Finally, the enzyme glycogen synthase removes these phosphate groups as it polymerizes glucose to form glycogen. the formation of glucose from noncarbohydrate molecules , such as amino acids, lactic acid, and glycerol

Glycogenolysis

is the The conversion/hydrolysis of glycogen to glucose 6-phosphate. The enzyme glycogen phosphorylase catalyzes the breakdown of glycogen to glucose 1-phosphate. (The phosphates are derived from inorganic phosphate, not from ATP, so glycogen breakdown does not require metabolic energy.) Glucose 1-phosphate is then converted to glucose 6-phosphate. The glucose-6-phosphate then may be oxidized via glycolysis or (in the liver) converted to free glucose for secretion in the blood. In most tissues, glucose 6-phosphate can then be broken down for energy (through glycolysis) or used to resynthesize glycogen.

-Glycolysis= A metabolic pathway that begins in cytoplasm for the breakdown of glucose for energy. Glucose—a six-carbon (hexose) sugar is converted into 2 molecules of pyruvic acid or pyruvate. Glycolysis is exergonic, and some energy that is released is used to drive the endergonic reaction ADP + Pi → ATP. At the end of the glycolytic pathway, there is a net gain of 2 ATP molecules per glucose molecule.

is the metabolic pathway by which glucose—a six-carbon (hexose) sugar is converted into 2 molecules of pyruvic acid, or pyruvate.

Excessive ___________ production by skeletal muscles can be associated with pain and muscle fatigue.

lactic acid

Under anaerobic conditions, the end-product of glycolysis is converted to

lactic acid.

Oxidation of a molecule occurs when the molecule ____, which must be coupled to the reduction of another molecule, which _____.

loses electrons accepts electrons

The addition of a phosphate group is known as ________.

phosphorylation

All of the following occur as events of one turn of the Krebs cycle/citric acid cycle EXCEPT ________.

production of three molecules of CO2

In glycolysis, glucose is converted to

pyruvate

Glycolysis is the metabolic pathway in which glucose is converted into two molecules of ____ In addition to pyruvate, glycolysis results in the production of two molecules of ____ Glycolysis releases energy, so it is____ When two hydrogen atoms are added to pyruvate, ____ is produced. In order for glycolysis to continue, there must be adequate amounts of ____ available, which is produced in the lactic acid pathway. The lactic acid pathway is a type of ____

pyruvate. NADH exergonic lactic acid NAD anaerobic metabolism.

In the formation of acetyl coenzyme A in aerobic respiration, NAD is __________ to NADH.

reduced

The sodium-potassium pump functions to pump

sodium ions out of the cell and potassium ions into the cell.

The formation of citric acid begins a cyclic metabolic pathway known as

the citric acid cycle, TCA Cycle (tricarboxylic acid), or the Krebs cycle (discovered by Sir Hans Krebs)