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

can engulf old organelles and invading pathogens, using its hydrolytic enzymes

digests and returns components for reuse by cell

Centrioles

Hollow cylinders containing microtubules arranged at right angles to each other

forms spindle fibres in cell division

Cytoskeleton

Provides mechanical strength and aids with transport within cells, enabling cell movement

Chloroplasts

Site of photosynthesis

where light energy is converted into chemical energy

Permanent vacuole

Stores water, ions and nutrients

maintains cell turgor pressure for support