AS Biology - Cell ultrastructure

AS Biology - Cells
Covering:
Cell ultrastructure
Cell organelles
Prokaryotes and Eukaryotes

Transcript

2. Living things • All living things are made up of cells and they all do: • Movement • Respiration • Sensitivity • Growth • Reproduction • Excretion • Nutrition
3. Microscopy Animal cell Plant cell
5. Nucleus • Contains DNA which codes for protein synthesis • Ribosomes are also formed here • Nucleolus processes ribosomes in the form of RNA • Nuclear pore allows mRNA to exit the nucleus • Nuclear envelope protects the nucleus from enzymes such as lysosomes
6. Ribosomes • Made up of a large and a small subunits of RNA • Use the information from the nucleolus to synthesize proteins
7. Endoplasmic Reticulum Rough • System of stacks • Has ribosomes attached on the outside • Synthesizes and transports proteins Smooth • Series of tubules • Synthesize and transport steroids
8. Golgi body/apparatus • Packages and processes proteins • Adds carbohydrates to proteins to make glycoproteins
9. Mitochondria (on) • Has it’s own DNA, ribosomes (in matrix) and double membrane • Membrane bends into cristae • Site of aerobic respiration • Produces ATP
10. Centrioles • 2 tubules perpendicular to each other • Contain 9 micro fibril triplets each • Chromosomes move here during nuclear division
11. Cell: Wall • Prevents cell from bursting • Allows cell to retain shape Membrane • Partially permeable • Controls what enters and leaves the cell
12. Lysosome (s) • “Suicide enzyme” • Contains digestive enzymes • Destroys worn out organelles and contents of vacuole by phagocytosis
13. Vacuole • Single membrane sac • Membrane is called tonoplast • Contains pigments, vitamins, minerals, organic acids and other substances • A change in its volume effects the turgidity of the cell
14. Chloroplasts • Has own DNA and a matrix called stroma • Stacks of membrane in stroma form granum which contain chlorophyll • Allows photosynthesis to occur • Pigments capture sunlight energy and transfer it into chemical bonds
15. Animal or Plant cell? Organelle Animal Plant Cell wall No Yes Cell membrane Yes Yes Mitochondria Yes Yes Endoplasmic Reticulum Yes Yes Golgi body/apparatus Yes Yes Lysosome Yes No Vacuole No (a small one if present) Yes Chloroplasts No Yes Centrioles Yes No Ribosomes Yes Yes Nucleus Yes Yes
17. • Single celled organisms • No membrane bound organelles • DNA is free in the cytoplasm • Ribosome size is 70s • Example: Bacteria
18. Eukaryotes • “True nucleus” • Cells that have membrane bound organelles • DNA in chromosomes within the nucleus • Ribosome size is 80s • Example: Animal/Plant cells
19. Prokaryote Eukaryote Both 70s ribosomes 80s ribosomes Ribosomes Free in cytoplasm In chromosomes in the nucleus Contain DNA Peptidoglycan cell membrane Cellulose or chitin cell membrane Cell membrane May contain plasmids Contain mitochondria Energy via aerobic respiration Can photosynthesize (individual species) Contain cytoplasm Flagella in arrangement of microtubules Flagella in arrangement of 9-2 microtubules Can have flagella present (individual species) Smaller in size Larger in size No nuclear membrane Double nuclear membrane No membrane bound organelles Contain membrane bound organelles
20. Viruses • Acellular (not made of cells) • No organelles • No chromosomes • No cytoplasm • Only replicate using a host cell • Mimicking the proteins that are usually taken in by cells • Example: HIV or Flu