Fox physiology Chapter 5

All of the reactions in the body that require energy transfer


Can be divided into an anabolism or catabolism


Requires the input of energy to synthesize large molecules


Releases energy by breaking down large molecules into small molecules


These reactions break down glucose fatty acids and amino acids serve as energy sources for the anabolism of ATP

Catabolic reactions

This process involves many oxidation reduction reactions


Complete catabolism of____ requires oxygen as the final electron acceptor


Breaking down glucose requires many enzymatically catalyzed steps the first of which are


Complete catabolism of glucose requires oxygen as a final electron acceptor this process is called

Aerobic cellular respiration

Aerobic respiration glucose occurs in 3 steps

1. glycolysis, 2. citric acid cycle (Krebs) 3. electron transport

Occurs in the cytoplasm anaerobic


Occurs in a matrix of the mitochondria aerobic

Krebs cycle (citric acid cycle)

Occurs in the crista of the mitochondria inner membrane aerobic

Electron transport

C6H12O6 + O2

6 H2O + ATP

The first step in catabolism of glucose


Glycolysis occurs in the

Cytoplasm of the cell

Glucose is split into two Pyruvic acid molecules

6 carbon sugar -> 2 MOLECULES of 3 carbon Pyruvic acid and C6 H12 O6-> 2 molecules of C3H4O3 ( sent to mitochindria )

In glycolysis, there is a loss of 4 hydrogen ions that are used to reduce 2 molecules of

2NAD + 4H -> 2 NADH+H (2NADH)

Exorgonic process -

Some energy is used to produce and drive the reaction ADP+P->ATP

How much net energy is gained in glycolysis

Four ATP molecules

Glucose requires activation at the beginning provided by 2P . Where does this come from

Stripped from two ATP molecules

Stripping two AP molecules from ATP prevent C glucose from diffusing back through the plasma membrane


2 ATP molecules gained


When there is no oxygen to complete the breakdown of glucose in NADH has to give away its electrons to Pyruvic acid. This results in the reformation of nad and the conversion of

Pyruvic acid to lactic acid

Muscle cells can survive without oxygen for a while by using

Lactic acid fermentation

RBCs can only use lactic acid fermentation because

They lack mitochondria

Also called anaerobic metabolism or lactic acid fermentation

Lactic acid pathway

Aerobic respiration formula

C6 H12 O6 +O2->6 CO2+ 6 H2O

Similar to combustion except energy is released in small enzymatically controlled steps not in large amounts of heat

Aerobic respiration

Begins with glycolysis that produces two molecules of pyruvic acid to NADH and 2 ATP

Aerobic respiration

Pyruvic acid will be used as a_____ called the citric acid cycle and NADH will be oxidized to make ATP

Metabolic pathway

Leaves the cytoplasm and enters the interior matrix of the mitochondria

Pyruvic acid (formerly glucose broken into 2 pyruvic acids)

____ is removed to form acetic acid

Carbon dioxide

_____ is combined with coenzyme A to form acytyl CoA

Acetic acid

TCA cycle also called

Citric acid or Krebbs cycle

It is a cycle because citric acid moves through a series of reactions to produce oxaloacetic acid again

Citric acid starts the citric acid cycle

Important events in the citric acid cycle

1 guanosine triphosphate GTP is produced which donate a phosphate group to ADP to form ATP 2.) three molecules NAD are reduced to NADH 3) one molecule FAD is reduced to FADH2 4) these events occur for each acetic acid so it happens twice for each glucose

Products for each glucose in the citric acid cycle

1) 6 NADH
2) 2 FADH2
3) 2 ATP
4) 4 CO2

Electron transport and oxidative phosphorylation

Occurred in folds of the cristae of the mitochindria are molecules that serve as electron transport
Including FMN coenzyme Q and several cytochrome 2) these accept electrons from NADH and FADH2 . These hydrogen are not transported with electrons3) oxidize

What is the function of electron transport molecules

They pass the electrons down the chain with each being reduced then oxidized

Energy produced is used to make ATP from ADP

It is an exorgonic reaction ATP is phosphorylate D-day process known as oxidative phosphorylaltion--- process is not 100% the difference is released as heat

Electron transport fuels proton pump which pump hydrogen from the mitochondria matrix to the space between the inner and the outer membrane this sets up huge concentration gradient between membranes. Hydrogen can only move through the inner membrane throu

Chemiosmotic theory

The coupling of electron transport to ATP production is a composed of two parts

Chemiosmotic theory and function of oxygen

The final electron acceptor without this acceptor the whole process would come to a halt


the citric acid cycle an electron transport require

Oxygen to continue

O2+ 4 e +4H-> 2 H2O

Formula for water reaction in body

Direct phosphorylation in glycolysis and the citric acid cycle yield 4 ATP These numbers are


___ in electron transport yields varying amounts of ATP depending on the cell and conditions.

Oxidative phosphorylation

Theoretically each n A d H yields 3 ATP and each FADH2 yields


_______. ___ yield is 36-38 per glucose

Theoretical ATP yield

Actual ATP yield

NADH yields 2.5 ATP and FADH2 yields 1.5 ATP.
Energy is needed to move the ATP out of the mitochondria into the cell cytoplasm. 1 glucose will actually yield 30 - 32 ATP

Cells can't store much of glucose because it will pull water into the cell via osmosis


Glucose is stored as a larger molecules called _____ in the liver skeletal muscle and cardiac muscle


Glycogen is formed from

Glucose via glycogenesis

Glucose is phosphorylated then


Glycogen synthase remove the___ and joins glucose together


In Glycogenolysis when the cell needs a glucose it breaks____ down again


In Glycogenolysis the cell produces glucose 1-Phosphate. _____. _____ is the catalyst

Glycogen phosphorylase

Glucose from glycogen is in the form glucose 1 - phosphate so it cannot leave

muscle or heart cells

The liver has an enzyme called _____ _ ____that removes the phosphate so glucose can we enter the bloodstream

Glucose 6 - phosphate

____ ____ can be used in cellular respiration to produce carbon dioxide and water skeletal muscles make too much so it shipped to the liver.

Lactic acid

The enzyme in the liver that converts lactic acid to pyruvic acid and NADH

Lactic acid dehydrogenase

The ____. ____ is where lactic acid is dealt with in the cells

Cori cycle

The liver can convert pyruvic acid to glucose 6-phosphate this can be used to make glycogen or glucose in the reverse of glycolysis. Glucose can return to muscle cells which completes the Cori cycle

The Cori cycle

___. And ____ can also be used for energy via the same pathways used for the metabolism of pyruvic acid

Lipids and proteins

When more food energy is taken into the body than is needed to meet the energy demands we can't store ATP for later instead of glucose is converted into ____. ___and ATP production is inhibited

glycogen and fat

As ATP levels rise after an energy rich meal production of___ is inhibited


Glucose doesn't complete glycolysis to form pyruvic acid and the acetyl CoA already formed is joined together to produce a variety of lipids including

Cholesterol keytone bodies and fatty acids

Fatty acids combined with glycerol to form _____ in the adipose tissue and liver

This process is lipogenesis

White adipose tissue is fat stored as


_____ breaking triglycerides down into fatty acids and glycerol using the enzyme latte


In this process fatty acids can enter the bloodstream as blood borne energy carriers and be used for energy elsewhere. Glycerol is then taken up by the liver and converted to glucose through gluconegenes


This type of fat is used in thermogenesis

Brown fat or brown adipose tissue

Liver cells convert fatty acids to acetyl CoA and then into

Ketone bodies

Ketone bodies circulate in the blood and they are

water soluble

Buildup of ketone bodies in the blood is called


when the right of lipolysis exceed the rate of fatty acid utilization (dieting diabetes )the concentration of fatty acids in the blood


Proteins provide ____for the body


____. _____ from dietary protein are needed to replace proteins in the body

Amino acids

If more amino acids are consumed than are needed the excess can be used for energy or converted into

Carbohydrates or fat

Our bodies can make 12 of the 20 amino acids from other molecules 8 of them must come from my diet and are called

Essential amino acids

Pyruvic acid and citric acid cycle intermediates called keto acid can be converted to by adding an ___ ___ . This process is called Transamination

Amne group

Dis there are more amino acids that needed the amine group from glutamic acid can be stripped and excreted

As urea in the urine

___. ____ sometimes form pyruvic acid or another citric acid cycle intermediate

Oxidative deamination

The formation of glucose from amino acids is called gluconeogenesis and occurs in the

Cori cycle

In oxidative deamination The main substrates are 3 - carbon molecules

Alanine, lactic acid glycerol

Glucose and ketone bodies come from

the liver

Fatty acids come from

Adipose tissue

Lactic acid and amino acid come from


The first step in cellular respiration


A common end product of red blood cells

Lactic acid

during this cycle the following things occur two molecules of FA dh2 are produced per molecule of glucose and addition of acetyl CoA to oxaloacetic acid start the cycle and GTP is produced and converted to ATP

Krebs cycle

Glycogen stored in this tissue can be used to produce free glucose


The product of beta oxidation is metabolized by the actions of

The Krebs cycle

Amino acid metabolism involves what

Oxidative Deanimation trans animation and the kreb cycle

A lack of blood glucose would have the greatest effect on

The brain

Metabolism of triglycerides utilizes

Beta oxidation

The common intermediate of carbohydrate protein and lipid metabolism is

Acetyl CoA