Respiration-5.7 Flashcards
What is the need for respiration?
-active transport
-endocytosis
-exocytosis
-synthesis of proteins (E.g. enzymes and antibodies)
-DNA replication
What are the 4 stages of aerobic respiration and where do they occur?
1- Glycolysis (cytoplasm)
2-Link reaction (mitochondrial matrix)
3-Krebs Cycle (mitochondrial matrix)
4-Oxidative phosphorylation (mitochondrial inner membrane cristae)
Label this
What is the function of the inner membrane of the mitochondria?
The inner membrane is:
Folded (cristae)
Less permeable (e.g. to small ions such as hydrogen ions)
The site of the electron transport chain (used in oxidative phosphorylation)
Location of ATP synthase enzymes (used in oxidative phosphorylation)
Has a large surface area for electron carriers and ATP synthase enzymes embedded in them
Describe the outer membrane of a mitochondria
-permeable to small molecules -it contains proteins some of which form channels or carriers that allow the passage of molecules such as pyruvate into the mitochondrion
Describe the matrix of a mitochondrion
Is an aqueous solution within the inner membranes of the mitochondrion
Contains ribosomes, enzymes and circular mitochondrial DNA necessary for mitochondria to function
What is the function of cristae in a mitochondrion?
-cristae (inner folds) increases surface area
-which enables the membrane to hold many electron transport chain proteins and ATP synthase enzymes
What are the stages of glycolysis?
-glycolysis is the first stage of respiration
Stages of glycolysis
-> PHOSPHORYLATION
-two molecules of ATP are hydrolysed, the released phosphate groups bind to glucose to make hexose bisphosphate
-> SPLITTING
-hexose bisphosphate (6 carbons) is split into two three carbon molecules of triose phosphate
->OXIDATION OF TRIOSE PHOSPHATE TO PYRUVATE
-dehydrogenase enzymes aided by coenzyme NAD remove hydrogens from triose phosphate, the two molecules of NAD accept the hydrogen atoms and become reduced
-two molecules of NADH are made for every molecule of glucose also four molecules of ATP are made for every two triose phosphate molecules undergoing oxidation
What are the products of glycolysis?
2x pyruvate
Net gain of 2 ATP
2x NADH
What are the stages of the Link Reaction?
Stage 2 of aerobic respiration
Stages of glycolysis:
->DECARBOXYLATION OF PYRUVATE (pyruvate was made during glycolysis)
-the carboxyl group is removed from from the pyruvate molecule
->NAD is reduced to form NADH
->the acetyl group combines with coenzyme a (CoA) to form Acetyl CoA
A teacher told his students that the human body makes the equivalent of its own mass in ATP every day
Explain why, at the end of the day only a small proportion of the student’s mass was ATP
(2 marks)
-because ATP is hydrolysed to ADP
-ATP is constantly recycled
(ATP used to provide energy for (active transport, exocytosis
ATP not stored long term/ used immediately)
Describe two ways in which the structure of mitochondrial membranes is related to the function of a mitochondrion
(2 marks)
Explain why early eukaryotes were able to grow more quickly than cells that did not possess mitochondria
(3 marks)
