Bio 108 Module 4 - The working cell

What is energy?

The capacity to cause change.

What are the two main forms of energy?

Kinetic energy and potential energy.

What is kinetic energy?

Energy of motion.

What is potential energy?

Stored energy due to an object's location or structure.

What is chemical energy?

Potential energy stored in chemical bonds.

What is the First Law of Thermodynamics?

Energy cannot be created or destroyed, only converted from one form to another.

What is the Second Law of Thermodynamics?

Every energy conversion increases entropy and releases some energy as heat.

What is entropy?

A measure of disorder or randomness in a system.

What is heat?

Kinetic energy associated with the random movement of atoms and molecules.

What happens to entropy during energy conversions?

Entropy increases.

What are reactants?

Starting substances in a chemical reaction.

What are products?

Substances formed by a chemical reaction.

What is activation energy?

The energy required to start a chemical reaction.

Do all reactions require activation energy?

Yes.

What is ATP?

Adenosine triphosphate, the main energy currency of cells.

What are the three parts of ATP?

Adenosine and three phosphate groups.

Why is ATP called the energy currency of the cell?

It stores and transfers energy for cellular work.

What happens when ATP is broken down?

ATP loses a phosphate group and becomes ADP, releasing energy.

What does ATP break down into?

ADP and a phosphate group (P).

What is ADP?

Adenosine diphosphate, a lower

How is ATP regenerated?

Energy from cellular respiration adds a phosphate group back to ADP.

Where is ATP regenerated?

Primarily in the mitochondria during cellular respiration.

What is cellular respiration?

The process that breaks down food molecules and captures energy in ATP.

What is metabolism?

The sum of all chemical reactions in an organism.

What is a catalyst?

A substance that speeds up a chemical reaction without being consumed.

What is an enzyme?

A protein catalyst that speeds up chemical reactions in living organisms.

What is a substrate?

The reactant an enzyme acts on.

What is an active site?

The specific region of an enzyme where the substrate binds.

How do enzymes speed up reactions?

By lowering activation energy.

Are enzymes used up during reactions?

No, they can be reused.

What is induced fit?

The slight change in enzyme shape when the substrate binds.

What is passive transport?

Movement of substances across a membrane without using cellular energy.

What is active transport?

Movement of substances across a membrane using cellular energy (ATP).

What direction does passive transport move substances?

Down a concentration gradient.

What direction does active transport move substances?

Against a concentration gradient.

Does passive transport require ATP?

No.

Does active transport require ATP?

Yes.

What is a solution?

A mixture in which a solute is dissolved in a solvent.

What is a solute?

The substance being dissolved.

What is a solvent?

The substance doing the dissolving.

What is a concentration gradient?

A difference in concentration between two areas.

What is diffusion?

The movement of molecules from an area of high concentration to low concentration.

Is diffusion passive or active transport?

Passive transport.

Example of diffusion?

Perfume spreading through a room.

What is osmosis?

The diffusion of water across a selectively permeable membrane.

Is osmosis passive or active transport?

Passive transport.

Example of osmosis?

Water moving into plant roots.

What is facilitated diffusion?

Passive transport that uses transport proteins to move substances across a membrane.

Is facilitated diffusion passive or active transport?

Passive transport.

Example of facilitated diffusion?

Glucose entering a cell through a carrier protein.