National 5 Biology Unit 1 - Cell Biology

Osmosis

The movement of water molecules from an area of higher water concentration to an area of lower water concentration, across a selectively permeable membrane.

Diffusion

The movement of small molecules from an area of high concentration to an area of low concentration, down a concentration gradient.

Name the two components of the cell membrane

Proteins and phospholipids

Active transport

Movement of molecules from an area of low concentration to high concentration, against a concentration gradient.

Double stranded helix

Describe the structure of DNA

Adenine, Thymine, Guanine and Cytosine

Name the four bases that make up DNA

Guanine

Which base is a complimentary base pair for Cytosine

Thymine

Which base is a complimentary base pair for Adenine

Chloroplast

Site of photosynthesis

Ribosome

Site of protein synthesis

Nucleus

Controls all cell activites

Cytoplasm

Site of many chemical reactions

Cell membrane 

Controls what molecules can enter and exit the cell

Cell wall

Provides structure and support to the cell