Chapter 25: Metabolism and Nutrition

Refers to all of the chemical reactions that occur in the body

Metabolism

Two types that make up the metabolism

Catabolism & Anabolism

Breaking down of complex organic molecules into smaller ones

Catabolism

Simple molecules built up into more complex molecules

Anabolism

____ is the body's preferred source for synthesizing ATP

Glucose

Glucoses use depends on the needs of the body cells which includes: 4

1. ATP Production

2. Amino Acid Synthesis

3. Glycogen Synthesis

4. Triglyceride Synthesis

Is a chemical reaction that splits a 6-carbon molecule of glucose into ___ of pyruvic acid

Glycolysis, two 3-carbon molecules

Glyco: Glucose gives off __/__ to get ___

ATP/ADP, Glucose-6-Phosphate

Glucose-6-Phosphate converts to ___

Fructose-6-Phosphate

Fructose-6-Phosphate gives off __/__ to get __

ATP/ADP, Fructose-1,6-Biphosphate

Fructose-1,6-Biphosphate converts to __ & __

GLAP & DHAP

GLAP and DHAP gives off ___+___/___ to get ___

2NAD + 2Pi/2NADH, 1,3-Bisphosphoglycerate

1,3-Bisphosphoglycerate gives off __/__ to get ___

2ADP/2ATP, 3-Phosphoglycerate

3-Phosphoglycerate converts to ___

2-Phosphoglycerate

2-Phosphoglycerate converts to ___

Phosphoenolpyruvate

Phosphoenolpyruvate gives off __/__ to get ___

2ADP/2ATP, Pyruvate

If there is oxygen available then ___ will be sent to the ___

Pyruvate, Krebs cycle

If oxygen is not available then ___ will be converted into ___

Pyruvate, 2 molecules of lactic acid

Pyruvate takes in __, gives off __ to get __

NADH, NAD+, Lactate

If enough oxygen is present, the TWO pyruvate molecules will be used to make TWO ___ which will enter the krebs cycle

TWO Acetyl-CoA molecules

The Krebs cycle occurs in the __ of the __

matrix of the mitochondria

Glycolysis is an aerobic/anerobic reaction

anaerobic

The Krebs cycle is an aerobic/anerobic reaction

aerobic

Is a series of electron carriers (FMN, cytochromes, iron-sulfur, copper, Co-Q, and intergral membrane proteins in the inner mitochondrial membrane

Electron Transport Chain

Each electron carrier in the chain is ___ to pick up electrons __ as it gives up electrons

reduced, oxidized

As electrons pass through the chain, a series of ___ reactions release small amounts of energy, and the energy is used to produce ATP. This process is known as ____ ____

exergonic reactions, oxidative phosphorylation

Electron Transport Chain process:

1. Energy from NADH + H+ or FADH2 passes along the electron transport chain and is used to pump H+.

2. A high concentration of H+ accumulates between the inner and outer mitochondrial membranes

3. ATP synthesis then occurs as hydrogen ions flow into the mitochondrial matrix through a special type of H+ channels in the inner membrane.

Glycolysis produces __ total ATP, _ ATP plus _ or _ from 2NADH + H+

6-8 ATP total, 2 ATP plus 4 or 6 from 2 NADH + H+

Formation of Acetyl CoA: 2NAD+ H + = __ ATPs from ETC

6 ATP

Krebs cycle and ETC produces _ ATP from GTP, _ ATP from 2FADH2, _ ATP from 6 NADH + H+

2 ATP, 4 ATP, 18 ATP

Total, __-__ ATPs are produced for each glucose molecule

36-38 ATPs

If glucose is not needed immediately for ATP production, it combines with other molecules to form glycogen.

Glycogenesis

Insulin from pancreatic __ cells, stimulate the ___ and ___ to undergo glycogenesis.

beta, hepatocytes, and skeletal muscle cells

Roughly about __% of glycogen rest in skeletal muscles and about __% in the liver

75%, 25%

When the body requires ATP, glycogen is stored in hepatocytes is broken down into glucose and released into the blood to be transported by the cells. The process is stimulated by __ and __.

Glycogenolysis, glucagon & epinephrine

Glycogenesis: Blood glucose -> ATP/ADP with hexokinase -> Glucose-6-phosphate -> ____ -> Uridine diphosphate glucose -> ___

Glucose-1-phosphate, glycogen

Glycogenolysis: Glycogen -> ___ -> Glucose-6-phosphate -> ___ -> blood glucose

Glucose-1-phosphate, glucose

When the body (liver) is low on glycogen, eat. If not, your body catabolizes ___ & ___. The glycerol part of __, __, and certain ___ can be converted by the liver into glucose. This process is stimulated by ___ and ___.

Glyconeogenesis: triglycerides & proteins. triglycerides, lactic acid, amino acids. cortisol & glucagon

Glycerol, lactic acid, certain amino acids -> pyruvic acid -> ___ -> ___ -> glucose

Glyconeogenesis: Glyceral-3-phosphate, Glucose-6-phosphate

Lipid Transports: 4

Chylomicrons, Very-low density lipoproteins, low-density lipoproteins, high density lipoproteins

Form in the mucosal epithelial cells of the small intestines, transport dietary lipids to adipose tissue for storage

Chylomicrons

Transport triglycerides synthesized by the hepatocytes to adipocytes for storage. As they deposit some of their triglycerides in adipose cells VLDLs are converted into LDLs

Very-low density lipoproteins

They carry about 75% of total cholesterol in blood and deliver it to the cells throughout the body for use in repair of cell membranes and synthesis of steroid hormonesand bile salts. Within the cell LDL is broken down and the cholesterol is released. Excess of LDLs due to lack of receptors cause the decrease in removing the LDL from the blood which can result in the build up of fatty plaques. "bad" cholesterol.

Low-density lipoproteins

Remove excess cholsterol from the body cells and the blood and transport it to the liver for elimination. "Good" cholsterol

High-density lipoproteins

In order for muscle, liver, and adipose tissue to oxidize the fatty acids from triglycerides to produce ATP. The triglycerides must first be split into ___ and ___. It is stimulated by ___, __, and ___

Lipolysis - glycerol and fatty acids. epinephrine, norepinephrine, & cortisol

Fatty acids are catabolized differently than glycerol and yield more ATP. The first stage is known as ___. enzymes remove 2 carbon atoms and create ___ that enter the krebs cycle.

Lipolysis: Beta oxidation. 2 acetyl Co-A molecules

Lipolysis: Hepatocytes can also take 2 acetyl CoA molecules at a time and condense them to form ___. Some aceto acidic acid is converted into ___ and ___. The formation of these are known as ___ by a process called ___.

Lipolysis: acetoacid acid. beta-hydroxyacetone & acetone. Ketone bodies, ketogenesis

Lipogenesis: Certain amino acids create acetyl CoA and go into the Krebs cycle. Glucose converts to ___ -> glycerol -> triglycerides. Acetyl CoA converts to ___ to triglycerides

glyceraldehyde-3-phosphate, fatty acids

Lipogenesis is stimulated by ___. This occurs when individuals consume more calories than needed. Proteins and fats can be created into triglycerides as well

Insulin

Stimulated mainly by ___. Proteins are broken down into amino acids. Hepatocytes convert some amino acids to ___, __, or ___. Before amino acids can enter the krebs cycle, their amino group must first be removed by a process called ___. The hepatocytes produces ___. the liver cells then create the ammonia to ___ which is excreted into the urine.

Protein catabolism. Cortisol. Fatty acids, ketone bodies, or glucose. deanimation. ammonia. urea.

__, thyroid hormones, insulin, ___, and __ stimulate protein synthesis directed by DNA and utilizes RNA and __. Weight bearing exercise increase bone and muscle mass.

Protein Anabolism. IGF, estrogen, testosterone. Ribosomes.

There are __ essential amino acids of the 20.

10

Blood glucose can go into most tissues and oxidize into CO2, water, and ATP. Blood glucose could also go into storage in the skeletal muscle.

Absorptive State

From the GI tract: Amino Acids -> hepatocytes in the liver -> proteins. -> keto acids -> CO2, water, and ATP. keto acids -> fatty acids to triglycerides to VDLs to triglycerids in adipose tissue. -> keto acids to glucose to glycogen or glyceraldehyde-3-phosphate to triglycerides to VDLs to triglycerides in adipose tissue.

Absorptive state

From the GI tract: Glucose -> glycogen or glyceraldehyde-3-phosphate -> triglycerides in adipose tissue. Or Glucose -> in adipose to fatty acids and glyceraldehyde-3-phosphate -> triglycerides

Absorptive state

From the GI tract: Triglycerides in chylomicrons to triglycerides in adipose tissue

Absorptive state

Factors that affect heat production: 6

Exercise, hormones, nervous system, body temperature, ingestion of food, age

Heat transfer: 4

convection, conduction, radiation, evaporation