Honors Biology Unit 1

For Honors BIology Unit 1

Passive Transport

The movement of molecules across a cell membrane without the use of energy, occurring along the concentration gradient.

Active transport

The movement of molecules across a cell membrane using energy, typically against the concentration gradient.

Selectively permeable

A characteristic of cell membranes that allows some substances to pass through while restricting others, playing a crucial role in maintaining cellular homeostasis.

Cell membrane

A biological barrier that separates the interior of the cell from the outside environment, allowing certain substances to pass while restricting others. It is composed of a phospholipid bilayer with embedded proteins, which aid in transport and communication.

Phospholipid

A type of lipid molecule that is a fundamental component of cell membranes, consisting of two fatty acid tails and a phosphate group head that is hydrophilic.

Membrane protein

Integral or peripheral proteins that are embedded in or associated with the cell membrane, playing roles in transport, communication, and cell signaling. They help control what goes into and what leaves the cell.

Diffusion

The process by which molecules move from an area of higher concentration to an area of lower concentration without the need for energy, often across a selectively permeable membrane.

Hypotonic

Stuff outside of cell has higher concentration of soluent than inside cell. Causes cell to swell up.

Isotonic

[solutes] is the same inside and outside of cell. Water molecules move equally in both directions

Hypertonic

Stuff outside cell has lower concentration of water than inside cell. Causes cell to shrink.

Solute

Thing that gets mixed with a solvent to form a solution

Ex: Water is solvent, salt is solute, together they for a solution of salt water

Macromolecules

Very large amount of smaller molecules combined.

Ex: Combination of protein molecules turns into Hemoglobin actin.

Carbohydrates

Monosaccharide

Polymer: Glucose and Starch

Quick source of energy

Lipids

Fatty acid & glycerol

Polymer: Triglyceride phospholipid

High energy storage

Nucleic Acids

Nucleotide

Polymer: DNA

Genetic Information

Protiens

Amino Acids

Polymer: Hemoglobin Actin

Structural Component