the 1st uni cram (1) Flashcards
Two things cells can be?
Complete unicellular organisms, with the ability to survive alone
Foundation of specialised tissue within multicellular organism
What surrounds cells?
Double layer of phospholipids
What do phospholipids do?
Allows for segregation of the internal environment of the cell from the external environment
Provides cellular support
Allows for the regulation of absorption and excretion of molecules
What is a catabolic reaction?
Breaking down molecules into smaller molecules to produce energy
What is an anabolic reaction
Making large molecules up from smaller building-block
What are metabolic reactions (catabolic and anabolic) reactions catalysed by?
Catabolic:
Glycolysis (Glucose to pyruvate)
De-amination of amino acids
Anabolic:
Protein biosynthesis
Lipid biosynthesis
Similarities between all reproduction forms
Synthesis of various enzymes for DNA replication
DNA replication produces two identical set of DNA
Additional protein synthesis
Cytokinesis of cells
prokaryotic cells
No nucleus or membrane bound organelles
cell walls present in prokaryotic cells
circular DNA
Eukaryotes
Nucleus and membrane-bound organelles
Linear DNA
Uni cellular/colony forming/multicellular
what are organelles
Specialised subunits that provide a specific function for cellular survival
Why is it useful to compartmentalise a biological function
Allows cells to be large and more efficient
Why are organelles mostly segregated from the internal cellular environment?
Allows formation of different internal cellular conditions
How are organelles segregated from the internal cellular environment
phospholipid bilayer
Nucleus: Structure
Large membrane bound organelle
External membrane is studded with nuclear pores
Condensed chromatin
Nucleolus
Nucleus: Function
Nuclear pores allows for passive diffusion of small water soluble molecules. Larger proteins have to get active transport across
Chromatin allows for storage of DNA, preventing damage, regulates gene expression and DNA replication
Endoplasmic Reticulum: Structure
Network of cisternae (membranes) held together by a cytoskeleton
Rough: Has ribosomes
Smooth: Highly folded membranes
Endoplasmic reticulum: Function
RER:
Helps protein synthesis
Aids in correct protein folding (RER chaperone proteins)
Allows for packaging and transportation of secretory proteins into vesicles
ER:
Aids in producing and packaging hydrophobic molecules (lipids/phospholipids/steroids)
Golgi apparatus: Structure
Stacks of individual stacked and flattered membrane enclosed disks
Cis:
Vesicles from the ER bind to the golgi
Trans:
New outgoing vesicles bud from golgi
Each stack has a different and specific enzymes
Golgi apparatus: Function
receiver and dispatcher of all proteins
Proteins get modified by addition of sugars and lipids
GA repackages the modified protein into a new vesicle unit.
Mitochondria : Function
Produces ATP via Phosphorylation of ADP
Done by forming a proton gradient between the intermembrane space and matrix across inner membrane
Gradient produced via pumping H+ ions across the inner membrane q
Electrochemical gradient is then used to fuel the production of ATP
Chloroplast : Structure
Double layer membranes of the chloroplast envelope
Protein rich alkaline fluid stroma
Thylakoids filled with photochemical protein systems
Stroma
Ribosomes
Chloroplasts : Function
Site of photosynthesis
Photons get harvested via Light harvesting complex then get taken to PS2
Energy used to split H2O and funnel H+ ions across the thylakoid membrane
What is Cellular Differentiation
The process a stem cell changes from one type to a differentiated cell (Pulri/totipotent to a more specific cell type)
Differentiation changes the cells size/shape/membrane/metabolic activity (Done by the expression of specific genes)
Red Blood Cell: Structure –> Function
No nucleus
Bowed disk shape –> Greater SA
Cytoplasm filled with haemoglobin
Little cellular content to allow more haemoglobin to fit
Increased flexibility
Enterocyte cells: Structure –> Function
External surface covered in microvilli:
folding of membrane increases SA of cell surface
More carrier proteins and digestive hydrolases present in microvilli
(Increases the absorption efficiency, completes final stages of external cellular digestion)
Increased gap junctions between Enterocytes and surrounding cells
(Allows for increased efficiency of nutrients)
Sperm Cell: Structure –> Function
compact nucleus head called acrosome
(Filled with spermlysin)
Spermlysin fuses sperms plasma membrane with egg’s plasma membrane
Lots of mitochondria to fuel movement of axial filament
Long flagellum to provide movement to the cell
Hepatocyte cell: Structure –> Function
Cytoplasm is rich with organelle that facilitate biosynthesis of proteins and lipids (Contains RER/ER, Golgi, mitochondria)
Produces detoxification enzymes
Blood capillary facing membranes are covered in micro-villi (Greater SA for absorption/excretion)
Bile canaliculus:
Allows for easy excretion of bile
Palisade Cells: Structure –> Function
Densely packed cytoplasm filled with chloroplast
Palisade cells found on the topside of the leaf structure (more Lux reaching chloroplasts)
Large dense vacuole (Increased H2O concentration in palisade cells, greater photosynthetic efficiency)
