BIO 101 Chapter 4 Obj jc

What is Energy

Ability to do work, capacity for change

Potential Energy

Stored energy

Kinetic Energy

Energy of motion

3 Types of Work Required by Cells

Chemical

Transport

Mechanical

First law of Thermodynamics

Energy cannot be created or destroyed, but it can be converted to other forms

Second Law of Thermodynamics

Every energy change increases disorder, loses some energy as heat

Entropy

Measure of randomness or disorder

What is Metabolism

Sum of all chemical reactions that happen inside a cell or organism

Exergonic Reactions

Release energy (respiration)

Endergonic Reactions

Require energy (photosynthesis)

Oxidation Reaction

A molecule loses electrons

Reduction Reaction

A molecule gains electrons

Oxidation-reduction (redox) reactions

One molecule loses electrons, another gains them, helps transfer energy in cells

Electron Transport Chain

Path of proteins that move electrons and make ATP

What is the Cellular Currency

ATP

3 components of ATP

Triphosphate
Ribose
Adenine

Exergonic Hydrolysis of ATP Equation

ATP + H2O => ADP + P + energy

Endergonic Dehydration of ATP Equation

ADP + P + energy => ATP + H2O

ATP/ADP Cycle

How cells recycle energy. ATP + Energy = lose one phosphate group and become ADP, releases energy. When cells need more energy, add a phosphate back to ADP to make ATP again

Phosphorylation

Adding a phosphate to a molecule to store or use energy

Enzymes

Catalysts that speed up chemical reactions

Active Binding Site

Part of enzyme where substrates fit and the reaction happens

Allosteric Binding Site

A different spot on the enzyme where a molecule can bind to, to change its shape to either help or stop the enzyme from working

Activation energy

Amount of energy required to start a chemical reaction

Negative Feedback

Controlling enzymes by slowing or stopping it from doing something

Competitive Inhibition

Inhibitor binds to the active site and competes with normal substrate, blocking it

Non-Competitive Inhibition

Inhibitor binds to allosteric site, changing the shape of the enzyme so the substrate can’t fit

Selective Permeability

Membrane admits some substances but excludes others

Concentration Gradients

A difference in concentration between adjacent areas

Passive transport

Transport that doesn't require input of energy

Diffusion

Movement of substances from high to low concentration until equilibrium

Simple diffusion

Diffusion that does not require assistance, moves down the concentration gradient (high to low)

Facilitated diffusion

Diffusion that requires assistance, moves down the concentration gradient (high to low)

Osmosis

Diffusion of water from high to low concentration across a semi permeable membrane until equilibrium

Terms of tonicity

Hypotonic

Hypertonic

Isotonic

Hypertonic

Solution has more solutes and less water outside of the membrane (shrink)

Isotonic

Same solutes and water concentration

Hypotonic

Solution has less solutes and more water outside of the membrane (swell)

Active Transport

Cells use energy to move substances from low to high concentration

Endocytosis

Cell takes things in by engulfing them

Exocytosis

Cell moves things out by fusing a vesicle with the cell membrane

Phagocytosis

Form of endocytosis where cell engulfs a large particle by surrounding then eating them