1- chemical level
2- cellular level
3- tissue level
4- organ level
5- system level
6- organismal level
The shape of a cell serves its function
For example :
- sperm cell
- smooth muscle cell
- nerve cell
- RBC
- Epithelial cell
Cell-cell communication
Cell (1) : send signal in a shape of hormone.
Cell (2) :
a- receive the signal via receptors on the plasma membrane.
b- send it inside.
c- translate it via biochemical machinery.
Typical structure of a cell
The Nucleus
-
The cytoplasm
Organelles
Endoplasmic Reticulum
Rough ER
- Ribosomes-attached (Protein synthesis) and ER for processing and sorting .
- synthesize phospholipids .
Smooth ER
- Extend from rough ER.
- synthesize fatty acids and steroids.
- contain enzymes that detoxify drugs.
- store Ca ion that triggers contraction in muscle cells .
Mitochondria
- The power house.
- Has its own DNA (from mother )
Golgi complex
Proteins are :
1- Modified.
2- Sorted.
3- Packed.
Ribosomes
Protein synthesis
1- free (used in cytosol).
2- attached to ER (secretion outside the cell).
Lysosomes
- Form from Golgi complex.
- Hydrolytic enzymes.
- Carry out :
1- autophagy.
2- autolysis.
3- extracellular digestion.
The cytosol
- 55% of cell volume.
- site of chemical reaction.
- contains dissolved particles .
The cell membrane
Introduction
Arrangement of membrane proteins
(Structurally)
Integral
Proteins
Peripheral
Proteins
Functions of membrane proteins
(Functionally)
1- Ion channel
(Integral)
2- Carrier/Transporters
(Integral)
3- Receptor (Integral)
4- Enzyme
(Integral and peripheral)
5- Linker (Integral and peripheral)
6- Cell identity marker (glycoprotein)