Download bacteria/archae. - No nucleus

CTR Revision Notes
Topic One
Prokaryote – bacteria/archae. - No nucleus - DNA found in a nucleoid Bacteria cells have an independent DNA molecule (plasmids – additional
genes) - Plasma membrane, single chromosome, ribososmes (protein
synthesis), stiff cell wall
Eukaryote – single celled organism (algae, amoebia, fungi, yeast) - Plasma
membrane surrounding cell - Cytoplasm (cytoskeleton, organelles, inclusions
and cytosol) - Nucleus - Intracellular material, membrane bound organelles
(endomembrane system)
Plasma Membrane - Nutrient movement, molecular transport - Ionic
composition and osmotic pressure - Endocytosis, exocytosis, communication Protein, carbohydrates, lipids - Glycoproteins and glycolipids – signal
transport - Phospholipid bilayer - Fluidity dependent on temperature, lipid
composition and cholesterol content
Cytoskeleton – filaments made of 3 proteins
Microtubules - Provide stability (cell shape, movement and intracellular
transport) - Microtubule organizing centre (centrosome in animals) Microtubules from centrosome move chromosomes in cell division - Cilia and
flagella (motile elements on cell surface containing microtubules) - Cilia (back
and forth), Flagella (rotate)
Actin Filaments - Shape, move cells, move organelles and cytoplasm - Form
from polymerization of actin molecules - Interact with myosin for movement Divide animal cells (cytokinesis)
Intermediate filaments - Cell shape - Keratins, nuclear lamins
Inclusions - Granules not membrane bound (glycogen, lipid droplets in
adipose tissue)
Organelles and other cellular components
Nucleus - Genetic material as chromosomes - Double membrane, outer
continuous with ER (endomembrane system) - Movement of RNA, proteins
(pores) - Lamina (network of proteins – shape, support membrane) Nucleolus (rRNA synthesis, ribosome’s assembled)
Endoplasmic Reticulum – largest organelle - Lipid and protein synthesis Rough ER – studded with ribosome’s (protein synthesis), more producing
secretory proteins - Ribosomes – ribosomal RNA and protein (protein
synthesis – cytosol (free ribosome’s), nuclear envelope (bound ribosome’s)) Smooth ER – fatty acid, phospholipids, steroid synthesis. Detoxify/modify
chemicals
Golgi Apparatus - Flattened membrane sacs surrounded by spherical
vesicles - Processing and transporting synthesised proteins into the ER
Mitochondria - ATP production -Double membrane - Permeable - Inner, less
permeable infoldings (cristae – organic molecules for ATP production, same
function as membrane enzymes in bacteria) - Eukaryotes - Own
DNA/Ribosomes
Lysosomes - Globular, single membrane - High C of enzymes (degrade
polymers – protein, lipids, polysaccharides, nucleic acid) - Degrade old cells
Peroxisomes - “Microbodies” – plant cells - Bud from ER, globular, single