Ch.3 Energy

to form ATP

glucose is broken down through metabolic pathways

energy

the capacity to do work

potential energy

stored energy/energy of position

kinetic energy

energy of motion

chemical energy

form of potential energy, released when bonds break

chemical energy is used for…

movement, synthesis, and concentration gradients

chemical energy is stored in….

• Triglycerides

• Glucose

• ATP

electrical energy

Movement of charged particle

mechanical energy

motion due to force

sound energy

compression waves from vibration

radiant energy

electromagnetic waves

heat energy

motion of atoms, measured as temperature

thermodynamics

energy can’t be created or destroyed; it also changes forms

metabolism

All biochemical reactions in living organism

reactants

starting substances

products

substances formed

exergonic reactions

release energy

endergonic reactions

require energy input

ATP cycling

continuously broken down and formed, it’s formed during exergonic reactions, hydrolosis releases energy for endergonic reactions

activation energy

energy needed to break bonds

increasing temp.

speeds up reactions

enzymes

biological catalysts that speed up reactions. low activation energy is needed and it increases rate of product formation

most enzymes are…

globular proteins, contain an active site

active site shape…

determines substrate binding

enzymes in action

substrate binds active site, enzyme changes chape, reactions occur, product is released and enzyme is reused

cofactors

help enzymes function

coenzymes

organic cofactors

Oxidoreductases

redox reactions

Transferases

transport molecules/groups

hydrolases

break bonds using water

Isomerases

rearrange molecules

ligases

join molecules

lyases

split bonds without water

enzymes usually end in

“-ase”

substrate concentration

Increased substrate increases reaction rate

optimal temperature for humans

40*C

enzyme pH

usually between 6-8; high pH denatures enzymes

Competitive Inhibitors

resemble substrate and compete for active site

Noncompetitive Inhibitors

bind allosteric site and change enzyme shape

Metabolic Pathways

series of enzyme-controlled reactions; product for one step becomes substrate for next

Multienzyme Complexes

groups of enzymes attached together

negative feedback

end product inhibits earlier enzyme & prevents overproduction

penicillin inhibits

bacterial enzymes

cellular respiration

oxidizes organic molecules & releases energy for ATP synthesis; also requires oxygen

Substrate-Level Phosphorylation

ATP formed directly from substrate energy

Oxidative Phosphorylation

energy transferred through electron carriers first

glycolosis

occurs in cytosol, doesn’t require oxygen

intermediate stage

occurs in mitochondria, Pyruvate converted to acetyl CoA

citric acid cycle

in mitochondrial matrix, required oxygen

Electron Transport System (function)

Transfers electrons from NADH and FADH₂

without enough oxygen

• Electron transport slows

• NADH accumulates

• NAD⁺ decreases

• Glycolysis would stop without NAD⁺ regeneration

fatty acids

• Broken down by beta oxidation

• Produce acetyl CoA

• Require oxygen

amino acids

• Enter pathways at different points

• Amine groups converted to urea

• Urea excreted by kidneys