cell structure

Nota:

• light and electron microscope ; used to see cells structure  in higher resolutions

1. plasma membrane

   Nota:

   • also known as cell membrane surface. It controls what enters and leaves the cell
2. nucleus

   Nota:

   • it is enveloped by two nuclear membrane. Contains chromosomes 
3. nucleolus

   Nota:

   • new ribosomes are made there 
4. ribosomes

   Nota:

   • structures made of RNA and protein. found in cytoplasm & attached to RER
   1. rough endoplasmic reticulum

      Nota:

      • Involve in protein synthesis and linking the amino acids. Moves amino acid chains from  cisternae of RER  to golgi apparatus.
      • the cisternae breaks off to form vesicles containing the amino acids
   2. smooth endoplasmic reticulum

      Nota:

      • Involve in synthesis of steroid hormones  and breakdown of toxins
5. Golgi apparatus

   Nota:

   • Here the amino acids are modified, for e.g adding a carbonyl group to the them. 
   • they break off  from GA to cell membrane by exocytosis.
6. Mitochondrion

   Nota:

   • mitochondria in plural, here also the mitochondria has 2 envelops surrounding them.
   • they are responsible for aerobic respiration, aka ATP production. Krebs cycle occur in matrix  and oxidative phosphorylation stage occurs on membranes of the cristae. 
7. Lysosomes

   Nota:

   • function: digest bacteria, unwanted or damaged organelles or other cells taken by phagocytosis within the lysosome.
   • they are little membrane-bound package of hydrolytic enzymes, aka digestive.
8. centrioles

   Nota:

   • found in animal cells; not in plant cells
   • They are made of tiny tubules called microtubules and they form spindle fiber during cell division, in animals cells

Nota:

• made up of
• DNa lies naked in the plasma; bacteria contains small plasmids made up of Dna, never associated with histone
• Contains only ribosomes, about 18 nm, and cell wall made up of  peptidoglycans

1. bacteria
2. archaea

Nota:

• They have nucleus and nuclear envelop. They are larger than prokaryotic cells

1. animals
2. plants
   1. chloroplasts

      Nota:

      • found only in some plants. Same nuclear envelop as mitochondria
      1. stroma

         Nota:

         • contains many paired based membranes thylakoids
         1. thylakoids

            Nota:

            • forms stacks called grana
            1. grana

               Nota:

               • the grana contains chlorophyll 
               1. chlorophyll
3. protista
4. fungi