Cell Structure Flashcards
Role of nucleus
• Contains genetic information (DNA)—> chromatin
• Transcription —> makes mRNA
• Nucleolus —> makes ribosomes
• Nuclear envelope contains nuclear pores- allows for compartmentalisation and movement of ribosomes and mRNA
• Outer membrane is continuous with RER
Role of RER
• Protein synthesis (translation)- transported through exocytosis
• Attached to nuclear envelope
• Flattened sacs of cisternae increases surface area
Role of Golgi Body
• Made of flattened sacs of cisternae
• MODIFICATION and PACKAGING of proteins
• Transports, modifies and stores lipids
• Lysosomes- vesicle containing lysozyme
Role of SER
• No ribosomes
• Synthesis and transport of lipids, steroids and hormones
Role of mitochondria
• Aerobic respiration and synthesis of ATP from carbs
• Double membrane- outer membrane controls the entry and exit of material, inner membrane is folded to form cristae
• Matrix contains loop of small circular DNA and 70S ribosomes
Role of ribosomes
• Made of protein and rRNA
• Has a small and large subunit
• Translation- protein synthesis to produce collagen and globular proteins
Role of lysosomes
• Contains hydrolytic enzymes
• Made by Golgi Body and RER
• Macrophages contain it to kill bacteria
•Autolysis
• Autophagy
Role of centrioles and microtubules
• 9+2 arrangement- 2 centrioles arranged at right angles, each consisting of 9 paired microtubules
• 2 centrioles forms a centrosome
• Spindle fibres produced and used in nuclear division
Role of microvilli
• Finger like extensions of the cell surface membrane
• Increases surface area of cell surface membrane
• For more efficient absorption or secretion
Role of cilia and flagella
• Identical structures but flagella is longer than cilia
• Whip like beating extensions
• Flagella are found in only some eukaryotic cells and many unicellular organisms
Role of chloroplasts
• Photosynthesis
• Double membrane- inner membrane is folded into lamellae (controls movement of substances in chloroplast)
• Stroma contains circular loop of DNA, 70S ribosomes and enzymes
• Grana is made up of flattened spaces of thylakoid membranes
• Starch grains are temporary stores of energy
Role of cell wall
• Made of cellulose and is fully permeable
• Encloses, supports and protects the cell
• Provides turgidity
• Contain plasmodesmata
Role of vacuole
• Holds cell sap
• Holds ions, water, salts, sugars, waste products
• Turgidity
• Hydrolysis reactions (water is present)
• Tonoplast (controls exchange between the vacuole and cytoplasm)
Structure of plant cells
• Cell wall made of cellulose
•Plasmodesmata
• Tonoplast
• Large central vacuole
• Chloroplast
• Nucleus
• Starch grains for storage
• Cytoplasm
Structure of Animal cells
• Small temporary vacuoles
• Cytoplasm
• Nucleus
• Centrioles
• cilia and flagella
Organelles that can be seen through a light microscope
• Nucleus
• Cell wall
• Chloroplast
• Chromosome
• Nucleolus
Role of phosphate ions
To make DNA/RNA/ATP/phospholipids
Role of Magnesium ions
To make chlorophyll
Role of nitrate ions
To make amino acids, which makes proteins for growth
Role of ATP (BAMTA)
B - bioluminescence/bulk transport
A - active transport
M - muscle contraction/movement
T - thermoregulation
A - linking anabolic and catabolic reactions together
Structure of prokaryotes
• Unicellular
•1-5 nanometers in diameter
• DNA not surrounded by nuclear membrane
• Loop of circular DNA
• 70S ribosomes
• No double membrane bound organelles
• No nucleolus
• Slime capsule
• Peptidogylcan cell wall
• Plasmids
Role of viruses
• Non cellular structures
• Contain genetic info in the form of DNA/RNA
• Protein coat —> capsid
• Capsomere
• Endoparasites in host organism
Role of plasmodesmata
• connects two cells
•facilitates movement of substances
• removes the need to pass membrane
• cell to cell communication
