Respiration Flashcards
What is respiration?
Process where energy stored in complex organic molecules is used to make ATP, occurs in living cells
What is energy?
Potential is storage, kinetic is energy of movement, moving molecules have KE that allows them to diffuse down concentration gradient. Large organic molecules contain chemicals potential energy. Energy cannot be created or destroyed only transferred, has many firms
Which is an anabolic reaction?
Biochemical reactions where large molecules are synthesised from smaller ones
What is catabolic reactions?
Biochemical reactions where larger molecules are hydrolysed to produce smaller ones
What metabolic processes require energy?
Active transport Secretion by exocytosis Endocytisis Synthesis of large molecules from smaller ones Replication of DNA and organelles Movement Activation of chemicals
What is a by product of catabolic reactions?
Release of energy as heat, useful as metabolic reactions controlled by enzymes, so temperature needs to be maintained
Where does energy come from?
Photoautotrophs use sunlight energy in photosynthesis to make large organic molecules that contain chemical potential energy, then available to others, respiration releases the energy, used to phosphorylate ADP to ATP, transfers energy to molecule
What is ATP?
Phosphorylated nucleotide, high energy intermediate in all cells, consisted of adenosine (adenine and ribose sugar) plus three phosphate groups. Can be hydrolysed to ADP and Pi releasing 30.6kj per mol, so energy available in small amounts, not wasted or damaging to the cell
What happens in the steps of respiration in terms of ATP
Energy released at each stage joins ADP and Pi to make ATP, it is continually hydrolysed and resynthesised, hydrolysis of ATP couples with synthesis reactions that require energy
What is a coenzyme?
Small non protein molecule that attaches to active site, just before or as substrate binds, take part in reactions and are changed, but recycled back to take part in faction again. Role is to carry chemicals between enzymes so link enzyme controlled reactions that are in a chain
What are the four stages of respiration?
Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation
Where do stages of reputation occur?
Glycolysis in cytoplasm of cells
Link and kerbs in matrix of mitochondria
Oxidative phosphorylation in cristae of mitochondria
Last three must be under aerobic conditions
What is NAD?
Organic, non protein molecule that helps dehydrogenase enzymes carry out oxidation reactions, nicotiana mode adenine dinucleotide, made from nicotinamide, ribose, adenine and two phosphate groups. nicotinamide can accept hydrogen atoms, to become reduced, oxidised when it looses them
What is NAD?
Organic bin protein molecule that helps dehydrogenase enzymes carry jut co enzymes are needed to help the reactions, h combined with coenzyme, reduced, and they carry hydrogen atoms which are later split to protons and electrons, to the inner mitochondrial membranes where they are involved in oxidative phosphorylation to produce ATP, coenzymes then recycled
Where is NAD used?
Glycolysis, link reaction, Krebs cycle and in anaerobic pathways
What is Coenzyme A?
Made from panthothebjc acid, adenosine, three phosphate groups and cysteine
What is the role of CoA?
Carry acetyl(ethanoate) groups made from our hate in link reaction onto the Krebs cycle, can also carry acetate groups made from fatty acids or amino acids. Makes acetyl coenzyme A
Why are alcoholics deficient in NAD?
Dehydrogenation of alcohol by dehydrogenase enzymes (ethanol>ethanal>ethanoic acid) hydrogens released combined with NAD so less available for respiration
Why is NAD a nucleic acid derivative?
Contains ribose sugar, nitrogenous base adenine, and phosphate groups
What is glycolysis?
Is a metabolic pathway where each glucose molecule is broken down to two molecules of pyruvate, occurs in cytoplasm of all living cells and is common to anaerobic and aerobic respiration
What is stage 1 of glycolysis?
Phosphorylation
Glucose is hexose sugar, stable molecule and needs to be activated so can be split
ATP hydrolysed, phosphate group released attached to carbon 6 on glucose, the glucose 6P changed to fructose 6P, isomers. Another ATP is hydrolysed phosphate attached to C1 of fructose to make fructose 1,6 bisphosphate energy from hydrolysed ATP used to activate hexose sugar and stops it moving out of cell- hexose 1,6 bisphosphate. Two ATP molecules are used
What is stage 2 of glycolysis?
Each hexose molecule split into two molecules of triose phosphate
What is stage 3 of glycolysis?
Oxidation as two hydrogen atoms are removed with dehydrogenase enzymes, aided by coenzyme NAD, a hydrogen acceptor to give reduced NAD,
At this stage time I molecules if NAD reduced per molecule of glucose
Two molecule of ATP are formed, substrate level phosphorylation
What is stage 4 of glycolysis?
Four enzyme catalysed reactions convert each triose phosphate to molecule of pyruvate, 3c compound, two molecules if ATP made by substrate level phosphorylation
What are the products of glycolysis?
Two molecules of ATP- 4 made but 2 used
Two molecules if reduced NAD
Two molecules of pyruvate, actively transported into mitochondrial matrix for link reaction, not in anaerobic conditions
What happens to hydrogens removed from triose phosphate?
Accepted by NAD to reduced NAD, cried indirectly to inner mitochondrial membranes and used to generate more ATP in oxidative phosphorylation
Which stage is ATP used?
Stage 1, to activate glucose, two molecule used.
Where is ATP produced?
Stage 3 and 4, 4 molecules made by substrate level phosphorylation, but 2 net production
Where is NAD used?
Stage 3, oxidation of triose phosphate
At which stage are isomerise enzymes used?
Stage 1, glucose 6P to fructose 6P
