KIN chapter 7

Production of Fuel

- body will break down lean muscle for AAs if not enough glc provided - give only fat: body must break down PRO tissue - give only PRO: body must convert AA to glc - BEST option is to balance all 3

Bulletproof diet

- eating only fat means your body has to resort to using its PRO stores to created glc

Production of fuel

- energy released during breakdown of macronutrients is called ATP - ATP powers all activites of living cells - we use ATP from catabolism for anabolism

Energy yielding pathway

- fatty acids cannot be used to make glc - if no CHO in diet, liver can make glc from pyruvate - PRO can be used to make glc if no CHO the burger picture pg. 211 in text**** 1) all of the energy yielding nutrients- protein, carbohydrates and fat can be broken down to acetyl CoA 2) Acetyl CoA can enter the TCA cycle 3) most of the reactions above release hydrogen atoms with their electrons, which are carried by coenzymes to the electron transport chain. 4) ATP is synthesized 5) hydrogen atoms react with oxygen to produce water.

Glucose Reactions

- glycolysis: break down of glc - Gluconeogensis: production of glc from a non - CHO source; this happens in the liver - keep yourself hydrated or your cells will shrivel and cause cramps. - always have to have balanced ions (- +)

Summary of chapter 7

- metabolism involves the catabolism and anabolism of molecules by a variety of cells in the body, and in particular, the liver. - the end result of metabolism is the production of ATP, the fuel used for all body processes. - the metabolism of glucose and fat yields pyruvate and acetyl CoA, both of which enter the TCA cycle and ATC to yield ATP - the transition of feasting to fasting involves the storage fuel, then the catabolism of fuel, to the production of new types of fuel. - while alcohol contributes fuel to the body, it contributes little else in terms of nutrition - alcohol is a narcotic and a depressant

Extra Energy

- pyruvate can convert to lactate for bursts of energy ; 400 m dash - pyruvate can convert to Acetyl CoA when prolonged energy is needed; 60 min jog

Fuel comes from the food we eat

- some fuels can be converted into glucose, some cannot vegetables; at least 2 kinds of at least half your serving starch; potatoes, rice, pasta protein; fish, lean meat, chicken beans, milk fruit

Highlight: Alcohol

-Ethanol: the kind we think of when we say "drink" -alcohol can dissolve lipids 'can quickly penetrate into cells; destroy cell structure (kills them), useful as antimicrobial for skin infections

Pyruvate and Acetyl CoA

-Pyruvate; 3 C compound Pyruvate CAN be used to make glc; parts of PRO and fat are converted to pyruvate -Acetyl CoA; 2 C compound Acetyl CoA CANNOT be used to make glc; parts of PRO and fat are converted to Acetyl CoA - Body prefers to use glc from food, will break down lean muscle to get AAs to make glc

Name one of the body's high energy molecules, and describe how it is used.

ATP is one of the body's high energy molecules. Notice that the bonds connecting the three phosphate groups have been drawn in wavy lines, indicating high energy bond. these bonds are broken, energy is released. ATP= A - P ~ P~ P each ~ denotes a "high energy" bond.

Brief review of digestion

CHO ---> glc & other monosaccharides for E

What are coenzymes, and what service do they provide in metabolism?

Coenzymes are complex organic molecules that work with enzymes to facilitate the enzymes activity. Many coenzymes have B vitamins as part of their structures. B vitamins are coenzymes for metabolism.

Brief review of digestion

Fat ----> glycerol & fatty acids for E

Energy balanced

Feasting - fat cells enlarge regardless of source of kcal - dietary fat to body fat is direct; dietary TG gets converted to TG in adipose tissue - sucrose: digest absorb change to pyruvate & acetyl CoA, make TG for storage in adipose FASTING - adaptations: - break down for E - glycerol and AAs to make glc - ketone bodies for brain E (last resort) - ketoacidosis: DM; sign that the pH of blood has shifted because of using ketones for fuel `acidic blood dentures PROs ` fruity breath ` ketonuria with ketonemia (elevated blood ketones) - metabolism slows to preserve tissue and minimize E loss. figure in text on pg 225

Name the four basic units derived from foods that are used by the body in metabolic transformations. How many carbons are in the "backbones" of each?

Four basic units are: glucose, glycerol, fatty acids, and amino acids. Carbons in backbones: Glucose has 6 carbons, glycerol has 3 carbons, a fatty acid usually has an even number of carbons commonly 16 or 18 carbons, an amino acid has 2 or 3 or more carbons with a nitrogen attached.

Brief review of digestion

PRO ----> AAs for building blocks for PROs

Catabolism

reactions in which large molecules are broken down to smaller ones. Catabolic reactions release energy.

Anabolism

reactions in which small molecules are put together to build larger ones. Anabolic reactions require energy

Metabolism

the sum total of all the chemical reactions that go on in living cells. Energy metabolism includes all the reactions by which the body obtains and expends the energy from food.