3.4: Eukaryotic cell structure

Double membrane which surrounds the nucleus. Often has ribosomes on its surface.
Function: controls the entry and exit of substances into and out of the nucleus and contains the reactions taking place within it.

Allows the passage of large molecules out of the nucleus

Granular, jelly like material that makes up the bulk of the nucleus

Consist of protein bound linear DNA.

A small spherical region within the nucleoplasm.
Function: Manufactures ribosomal RNA and assembles ribosomes

1. Act as the control centre of the cell through the production of mRNA and tRNA

2. Retain the genetic information of the cell in the form of DNA and chromosomes

3. Manufacture ribosomal RNA and ribosomes

Controls the entry and exit of material. The inner of the two membranes is folded to form cristae.

Provide a large surface area for the attachment of enzymes and proteins involved in respiration.

Contains proteins, lipids, ribosomes and DNA that allows the mitochondria to control the production of some of its own proteins.
Many enzymes involved in respiration are found in the matrix.

1. Site of aerobic respiration

2. Produce ATP from glucose

Site of photosynthesis

Stacks of thylakoids containing chlorophyll.
Where light absorption takes place

Fluid filled matrix where the second stage of photosynthesis takes place.

1. Granal membranes provide a large surface area for the attachment of chlorophyll, electron carriers and enzymes.

2. Fluid of the stroma possesses all the enzymes required in the second stage of photosynthesis

3. Chloroplasts contain ribosomes and DNA so they can quickly manufacture proteins needed for photosynthesis.

1. Provides a large surface area for the synthesis of proteins and glycoproteins.

2. Provide a pathway for the transport of materials.

1. Synthesise, store and transport lipids

2. Synthesise, store and transport carbohydrates

1. Add carbohydrate to proteins to form glycoproteins

2. Produce secretory enzymes

3. Secrete carbohydrates

4. Transport modify and store lipids

5. Form lysosomes

1. Hydrolyse material ingested by phagocytic cells

2. Release enzymes to the outside of the cell in order to destroy material around the cell

3. Completely breakdown cells after they have died

Hydrolyse the cell wall of bacteria

80s-larger

70s-smaller

1. Provides mechanical strength to prevent cell bursting under the pressure created by the osmotic entry of water

2. To give mechanical strength to the plant as a whole

3. To allow water to pass along it so contributes to the movement of water through the plant

1. 
   Make cells turgid

2. The sugars and amino acids inside may act as a temporary food store

3. The pigments may colour petals to attract insects