Cell structure- ultrastructure of eukaryotic cells

Cell structures + functions

Cell surface membrane

Regulates the passage of substances
Forms a protective barrier

Cytoplasm

Provides a medium for cellular processes

contains enzymes for metabolic reactions

Nucleus

The control centre 
stores genome

transmits genetic info

Nucleolus

Where ribosomes are made

Rough endoplasmic reticulum

Intracellular transport system 

cisternae form channels for transporting substances from one area of the cell to another

provides a large surface area for ribosomes

Ribosomes

Synthesises proteins that will be exported outside the cell

Smooth endoplasmic reticulum

Contains enzymes that catalyse reactions involved with lipid metabolism

Synthesis of cholesterol/lipids/steroid hormones

involved with absorbtion synthesis

transports lipids from gut 

Vesicle

Act as a packet for transporting substances like lipids and proteins within the cell

can be secretary

Golgi apparatus

Proteins are modified and packaged

adding sugar - glycoproteins

adding lipid - lipoproteins

Lysosomes

Surrounded by a membrane which protects it from digestive hydrolytic enzymes

can engulf old organelles and invading pathogens

digests and returns components for reuse by cell