2 Cell types & specialisation Flashcards
3 essential features of a cell.
1 Exterior plasma membrane - seperates cell from external medium.
2 Nuclear region with DNA genetic material.
3 Interior semifluid cytoplasm.
Two main cell groups:
Prokaryotic & Eukaryotic.
Prokaryotic:
No nucelus. Little internal organisation.
What organisms are prokaryotic?
Bacteria & Archaea.
Prokaryotic cell size:
0.5-2um in diameter.
Eukaryotic:
Distincy nucleus. Specialized internam organs. Uni or multicellular.
Eukaryotic cell size:
5-20um in diameter
5 Bacteria features:
1 Plasma membrane at edge of cytoplasm.
2 Rigid peptidoglycan cell wall - gram pos have only exterior cell wall. Gram neg have extra outer membrane with periplasmic space.
3 Relatively simple, undifferentiated cytoplasm.
4 Genomic DNA in ‘nucloid’ region not seperate from surround sytoplasm
5 DNA containing plasmids.
Gram positive vs gram negative.
Pos: thick peptidoglycan cell wall. Stains purple. No outer membrane. Susceptible to antibiotics.
Neg: thinner layer of peptidoglycan cell wall. Stains pink. Outer membrane of LPS.
Bacteria organelles: (3 points)
Flagella for movement.
Fibriae & pili for attachment to surcases/other bacteria.
Cyanobacteria have memebrane foldings for photosynthesis.
Archaea:
Found in hostile environments. Eukaryotes evolved from acheaea.
4 Eukaryotic features:
1 Plasma membrane at edge of cytoplasm.
2 DNA contained in nucleus, seperated from cytoplasm by membrane.
3 Cytoplasm compartmentalised with membrane bound organelles diverse functions.
4 Complex cytoskeleton maintains cell integrity (microtubules & filaments).
What organisms are eukaryotic?
Animals and Plants
Animal cells:
Nuclues. Plasma membrane. Nucleolus. Lysozyme. Mitochondira. Golgi body. Peroxisomes. RER. SER. Small vacuoles. Ribosomes. Centrioles. Cytoskeleton.
Plant cells:
Nuclues. Nucleolus. Leukoplast. Plasmodesmata. Plasma membrane. Mitochondira. Golgi body. Peroxisomes. RER. SER. Chloroplasts. Ribosomes. Cytoskeleton. Single large vacuole. Rigid cellulose cell wall.
Shared features in Eukaryotic and Prokaryotic cells: (7 features)
1 Similar plasma membrane.
2 DNA for genetic information with indentical code.
3 Transcription and translation with similar ribosomes.
4 Metabolic pathways (glycolysis & TCA).
5 Similar apparatus for conservation of chemical energy as ATP.
6 Similar photosynthesis.
7 Similar mechanism for synthesizing & inserting membrane proteins.
Features only in eukaryotes: (10 features)
1 Divsion of cells into nucleus and cytoplasm. Seperated by a nuclear enevelope containing complex pore structures.
2 Complex chromosome composed of DNA and associated proteins that are capable of compacting into mitotic structures.
3 Complex membranous cytoplasmic organelles (ER, Golgi complex, lysosomes, endosomes, perioxisomes and glycoxisomes).
4 Mitochondria for respiration
5 Chlroplasts for photosynthesis.
6 Complex cytoskeletal system - microtubules, intermediate filaments and microtubules.
7 Complex flagelle and cilia.
8 Pinocytosis, receptier mediated endocytosis and phagocytosis
9 Plants have cellulose containg cell walls.
10 Cell divison using a microtubule-containing mitotic spindle that seperates chromosomes.
Multicellularity allows ____________
Cell specialisation.
Movement structures:
Flagella and Cilia projections on surface allow proplulsion in portists/fungi.
Also, has roles in vertbrates in ears and airways.
Photosynthesis structures:
Chloroplasts concentrated in plant cells exposed to light.
Metabolism structures:
Adipose cells for fat storage - large lipid droplet.
Brown fat cells fopr heat production with mitochondria.
Signalling structures:
Nerve cells have terminal dendrites and long axon for electric signals.ra
Transport structures:
Erythrocytes specialised for gas transport (no nucleues or organelles when matured). Full of haemoglobin. Small & flexible.
Reproduction structures:
Sperm have flagellum. Mushroom spores produced on gills from specialised basidia.
