Parts of the cell
BIOCHEMISTRY 3(2+1)
Parts of the cell
|
The parts of the cell can be divided as
- Nucleus
- Cytoplasm
- Surface or cell wall
Nucleus
- One or more per cell
- Spherical shape
- Denser than surrounding cytoplasm
- The nucleus consists of the nuclear envelope, nucleolus, chromatin, and nucleoplasm.
Nuclear Envelope
- Structure
- two unit membranes with a fluid-filled space
- nuclear pores present
- outer membrane may be continuous with endoplasmic reticulum
- Function selectively permeable to control movement in or out contains nuclear contents
Chromatin
- Structure -composed of long thin strands of DNA
- Function -contains instructions that control cell metabolism and heredity
Nucleolus
- Structure non-membraneous matrix of RNA (ribonucleic acid) and protein
- Function
- instructions in DNA are copied here
- works with ribosomes in the synthesis of protein
Chromosomes
- Usually in the form of chromatin
- Contains genetic information
- Composed of DNA
- Thicken for cellular division
- Set number per species (i.e. 23 pairs for human)
|
|
Nuclear membrane
- Surrounds nucleus
- Composed of two layers
- Numerous openings for nuclear traffic
|
|
Nucleolus
- Spherical shape
- Visible when cell is not dividing
- Contains RNA for protein manufacture
|
|
|
|
|
|
|
|
Last modified: Tuesday, 17 January 2012, 9:08 AM