1. Active transport 3. Synthesis (protein)
2. Muscle contraction 4. Nerve transmission
inert
small = easy transport across membrane
universal energy currency: used by all organisms to provide energy for nearly all reactions
phosphorylation: ADP + Pi + 30.6 KJmol-1 → ATP
- endergonic (absorbs energy)
hydrolysis: ATP → ADP + Pi + 30.6 KJmol-1
- exergonic (releases energy)
catabolic – only 1 bond to break
catalysed by ATPase – only 1 enzyme needed
efficient release – only 1 molecule needed to break down
released in small amounts – little wasted as heat (uncontrolled release from glucose destroys cells)
a. ATP synthesis – electron transport chain: alternating proton pumps & electron carriers
- e- (from H) transferred down electron carriers on inner membrane
o redox: oxidation of NAD(P)H makes energy available
- energy for proton pumps: pump H+ across membrane = proton gradient
- Chemiosmosis: protons flow down gradient through stalked particles
- ATPSynthetase: ADP + Pi + energy from proton = ATP
o mitochondria: e- + H+ + oxygen = water
o chloroplast: e- + chlorophyll+ , NADP + H+
b. Mitochondria gradient across inner membrane between intermembrane space & matrix
Chloroplasts: gradient across thylakoid membrane between thylakoid space & stroma
c. proton gradient maintained by proton pumps using energy from electrons
d. Respiration – oxidative phosphorylation: energy from oxidation of NADH
Photosynthesis – photophosphorylation: energy from light
Investigate dehydrogenase activity using artificial hydrogen acceptors (methylene blue / DCPIP / tetrazolium)
- Independent/control: temperature + yeast concentration + methylene blue concentration
- Dependent: rate of dehydrogenase activity = time to lose colour
o Methylene blue: higher reduction potential (likelihood) than NAD/FAD
o Reduced: blue → colourless
o Use colorimeter to find % transmission - end-point/time taken is subjective
https://pmt.physicsandmathstutor.com/download/Biology/A-level/Notes/WJEC-England/Practical-Skills/SP%201.1%20-%20Dehydrogenase%20Activity.pdf
https://www.physicsandmathstutor.com/biology-revision/a-level-wjec-eduqas/practical-skills/dehydrogenase-activity-flashcards/
https://experiments.science.cymru/biology/19-investigation-of-dehydrogenase-activity-in-yeast/
2. Muscle contraction 4. Nerve transmission
inert
small = easy transport across membrane
universal energy currency: used by all organisms to provide energy for nearly all reactions
phosphorylation: ADP + Pi + 30.6 KJmol-1 → ATP
- endergonic (absorbs energy)
hydrolysis: ATP → ADP + Pi + 30.6 KJmol-1
- exergonic (releases energy)
catabolic – only 1 bond to break
catalysed by ATPase – only 1 enzyme needed
efficient release – only 1 molecule needed to break down
released in small amounts – little wasted as heat (uncontrolled release from glucose destroys cells)
a. ATP synthesis – electron transport chain: alternating proton pumps & electron carriers
- e- (from H) transferred down electron carriers on inner membrane
o redox: oxidation of NAD(P)H makes energy available
- energy for proton pumps: pump H+ across membrane = proton gradient
- Chemiosmosis: protons flow down gradient through stalked particles
- ATPSynthetase: ADP + Pi + energy from proton = ATP
o mitochondria: e- + H+ + oxygen = water
o chloroplast: e- + chlorophyll+ , NADP + H+
b. Mitochondria gradient across inner membrane between intermembrane space & matrix
Chloroplasts: gradient across thylakoid membrane between thylakoid space & stroma
c. proton gradient maintained by proton pumps using energy from electrons
d. Respiration – oxidative phosphorylation: energy from oxidation of NADH
Photosynthesis – photophosphorylation: energy from light
Investigate dehydrogenase activity using artificial hydrogen acceptors (methylene blue / DCPIP / tetrazolium)
- Independent/control: temperature + yeast concentration + methylene blue concentration
- Dependent: rate of dehydrogenase activity = time to lose colour
o Methylene blue: higher reduction potential (likelihood) than NAD/FAD
o Reduced: blue → colourless
o Use colorimeter to find % transmission - end-point/time taken is subjective
https://pmt.physicsandmathstutor.com/download/Biology/A-level/Notes/WJEC-England/Practical-Skills/SP%201.1%20-%20Dehydrogenase%20Activity.pdf
https://www.physicsandmathstutor.com/biology-revision/a-level-wjec-eduqas/practical-skills/dehydrogenase-activity-flashcards/
https://experiments.science.cymru/biology/19-investigation-of-dehydrogenase-activity-in-yeast/
