essay Flashcards
Glycolysis
-Phosphorylation of glucose using ATP
-Oxidation of triose phosphate to pyruvate
- Net gain of ATP
-NAD reduced
Link/Krebs/ETC(mitochondrion)
-Occurs in the matrix (mitochondrion)
-Pyruvate oxidised and decarboxylated into acetate
-Produces reduced NAD and CO2
-Acetate combines with coenzyme A to produce Acetyl co A
–Substrate level production of ATP/ ATP produced in Krebs cycle
-Production of reduced NAD/FAD
-electrons fed into ETC/ used in oxidative
-electrons pass along carriers/ through electron transport chain/ through a series of REDOX reactions
- energy released
-protons move into intermembrane space
-ADP + Pi through ATP synthase
Light dependent reaction
- Chlorophyll absorbs light energy and excites electrons
-Electrons removed via oxidation of chlorophyll via photo ionisation
-Electrons move along ETC releasing energy through a series of redox reactions
-Energy released by electrons used to form proton gradient
-H+ ions move through ATP synthase
-Provides energy to join ADP and Pi to for ATP
-photolysis of water to produce 2 H+, 2e- and 1/2 oxygen
-NADP reduced by hydrogen
Light independent reaction
-CO2 combines with RUBP
- produces two GP using enzyme rubisco
- GP reduced to triose phosphate
- Using reduced NADP
-Using energy from ATP
-Triose phosphate converted to glucose or regenerated back to RUBP
Synapse
-Depolarisation of presynaptic membrane
- Ca2+ channels open and Ca2+ enter synaptic knob
-Ca2+ cause synaptic vesicles to move and fuse with presynaptic membrane and release neurotransmitter
-neurotransmitter diffuses across synaptic left
- binds to receptors on post synaptic membrane
-Na+ enter post synaptic neurone and leads to depolarisation
Transcription
-mRNA attaches to ribosomes OR (mRNA attaches) to rough endoplasmic reticulum;
-tRNA anticodons bind to complementary mRNA codons;
-tRNA brings a specific amino acid;
-Amino acids join by peptide bonds via condensation reaction;
-Amino acids join together with the use of ATP
-tRNA released after amino acid joined to polypeptide
-The ribosome moves along the mRNA to form the polypeptide
Translation
-Hydrogen bonds between DNA bases break;
-Only one DNA strand acts as a template;
-Free RNA nucleotides align by complementary base pairing;
-in RNA Uracil base pairs with adenine in DNA AND In RNA Uracil is used in place of thymine;
-RNA polymerase joins adjacent RNA nucleotides;
-by phosphodiester bonds between adjacent nucleotides
-Pre-mRNA is spliced (to form mRNA) OR Introns are removed to form mRNA
Transpiration
-Evaporation/ transpiration from leaves
-creates cohesion and tension between water molecules
- Adhesion/ water molecules bind to xylem
- creates continuous column of water
Translocation
-In leaf sugars actively transported into phloem
- by companion cells
- lowers water potential of sieve cells and water enters by osmosis
-increase in pressure causes mass movement towards root
- sugars used in for respiration for storage
Phagocytosis
- Pathogen is engulfed by the phagocyte.
- Engulfed pathogen enters the cytoplasm of
the phagocyte in a vesicle - Lysosomes fuse with vesicle releasing
digestive enzymes - Lysosome enzymes break down the pathogen.
- Waste materials are ejected from the cell by exocytosis
vaccines
-Vaccine contains specific antigen from pathogen
-Macrophage presents antigen on its surface
-T helper cell with complementary receptor protein binds to antigen & becomes activated;
-T cell stimulates B cell by complementary receptor binding and releases cytokines;
-With complementary antibody on its surface
-B cell divides to form clone secreting / producing same antibody
-B cell secretes large amounts of monoclonal antibody
AIDS
- high viral load leads to increased destruction of helper T cells
- Less activation of B cells
-Less production of plasma cells so less able to kill virus infected cells - Less able to destroy other pathogens
Mitosis
Prophase:
-Nuclear membrane begins to breakdown;
-Centrioles move to poles of the cell;
-Chromatin supercoils and condense into chromosomes
-Chromosomes appear as 2 sister chromatids joined by a centromere
Metaphase:
-Spidle fibres form and attach to the centromere of each chromosomes
-Chromosomes align at the equator
Anaphase:
-Spindle fibres shorten
-Centromere splits and Sister chromatids are separated
-Chromatids pulled to opposite poles of the cell
Telophase:
Nuclear membrane begins to reform;
Chromosomes unwind
Meiosis
-Homologous chromosomes pair up; or form a Bivalent
-maternal and paternal chromosomes are arranged in any order
-Independent segregation
-Crossing over
-Equal Portions of chromatids are swapped between chromosomes
-Produces new combination of alleles
-Chromatids separated at meiosis 2
Starch digestion
-salivary Amylase
-Starch to Maltose
-Maltose to glucose using maltase
-Hydrolysis of Glycosidic bonds;
