Respiration Flashcards
1
Q
Glycolysis
A
location: cytosol
inputs: 1 glucose, 2ATP
products: 2ATP, 2NADH, 2 pyruvate
phosphorylation of sugars –> lysis –> oxidation by dehydrogenation –> substrate level phosphorylation
2
Q
link reaction
A
location: mitochondrial matrix
inputs: pyruvate
products: 2 CO2, 2 Acetyl CoA, 2NADH
- pyruvate undergoes oxidative decarboxylation to form acetyl CoA
3
Q
Krebs Cycle
A
location: mitochondrial matrix
inputs: 2 acetyl CoA
products: 2FADH2, 2ATP, 6NADH, 4CO2
- acetyl coA combines with oxaloacetate to form citrate, which id converted to a-ketoglutarate by oxidative decarboxylation, substrate level phosphorylation, oxidation and is converted to oxaloacetate
4
Q
Oxidative phosphorylation
A
- NADH and FADH2 donates high energy electron from glycolysis, link reaction and Krebs Cycle to the first electron acceptor of the electron transport chian
- the first electron carrier is reduced, hence NAD is regenerated and can pick up more electrons and protons from glycolysis, link reaction and Krebs cycle. The first electron carrier is reduced then transfers the electron to the next and reduces it while the first carrier is reoxidised
- the transfer of electrons continues until they reach the final electron acceptor, O2, which combines with H+ and electrons to form metabolic water via. cytochrome oxidase
- as electrons are passed down increasingly electronegative electron carriers in the ETC, energy is released which is used to actively pump protons from the mitochondrial matrix to the intermembrane space via the electron carriers, generating a proton gradient
- as protons diffuse through ATP synthase back into the mitochondrial matrix, chemisosmosis occurs to phosphorylate ADP to ATP
5
Q
anaerobic respiration
A
- glycolysis can still occur to produce a net 2 ATP per glucose molecule in the absence of oxygen as NAD needed is regenerated from fermentation reactions
- alcoholic fermentation occurs in yeast, lactic acid fermentation occurs in muscles of animals
- in animals –> pyruvate is reduced to lactate by lactate dehydrogenase
- in yeast –> pyruvate is converted to ethanal which is reduced to ethanol in the presence of alcohol dehydrogenase
- 19 times lower compared to aerobic respiration which produces 38 ATP molecules
6
Q
Cell Theory
A
- cells are the smallest unit of life
- all cells come from pre-existing cells
- living organisms are composed of cells
7
Q
Nucleus
A
- to contain hereditary material
- to control cell activities by regulating protein synthesis
- contains enzymes for DNA replication, transcription and RNA processing
8
Q
Nucleolus
A
- to synthesise rRNA
- site of assembly of rRNA and proteins into large and small ribosomal subunits using rRNA
9
Q
chromatin
A
- DNA contains genes which undergo transcription in nucleus to form mRNA which then undergo translation at ribosomes to form polypeptides
10
Q
rough ER
A
- to transport proteins which are synthesised by the ribosomes on its surface to the Golgi apparatus via transport vesicles
- to allow proteins to fold into their native conformation
- to glycosylate proteins hence forming glycoproteins
11
Q
smooth ER
A
- to synthesise lipids and carbohydrates
- to detoxify drugs and poisons
12
Q
Golgi apparatus
A
- to glycosylate proteins and lipids to form glycoproteins and glycolipids respectively
- to modify existing glycoproteins and glycolipids by cleaving existing sugar chains
- to sort, package proteins and target proteins to different parts of the cell or for secretion out of cell
- to form lysosomes
- to synthesise polysaccharides such as pectin which is transported in vesicles to the cell surface membrane
13
Q
lysosome
A
- to digest material taken in by the cell by endocytosis
- to release enzymes from cells by exocytosis for extracellular digestion
- to digest unwanted or worn out organelles
- to self-destruct a cell after its death
14
Q
mitochondrion
A
- site of aerobic respiration to generate energy in the form of ATP
15
Q
chloroplast
A
- contain chlorophyll which convert solar energy to chemical energy through photosynthesis
