12.6 part 1 Flashcards
Require energy for:
muscle contractibility
maintaining body temperature
active transport
ATP is made in the…
light-dependent stage of photosynthesis and is used to make carbohydrates in the light-independent stage
ATP that is need for energy-requiring processes in the cell are produced in…
cellular respiration
Respiration is…
a series of reactions in which energy is transferred from inorganic compounds, carbohydrates, to the temporary energy store, ATP
Respiration occurs in the…
mitochondria
4 stages of respiration:
1) Glycolysis
2) Link reaction
3) Krebs cycle
4) Electron transport chain
glycolysis occurs in:
cytoplasm
link reaction and krebs cycle occurs in:
matrix of mitochondria
electron transfer chain occurs:
inner membrane of mitochondria
Coenzymes are:
complex inorganic molecules used by enzymes to accept or donate molecules involved in a reaction
Often referred to as ‘helper’ molecules as they carry chemical groups or ions about
Glycolysis known as…
carbohydrate splitting
Glycolysis is anaerobic and has 2 stages:
1) Phosphorylation
2) Oxidation
G- During phosphorylation:
Glucose is phosphorylated by adding 2 phosphates from 2 ATP molecules
Glucose is split due to hydrolysis
2 molecules of triose phosphate are created and 2 ATP molecules are used
G- During oxidation:
4 ATP are produced, (2 used at start) so net gain of 2 ATP
Coenzyme NAD+ collects the hydrogen ions forming a reduced NAD+
The triose phosphate is oxidised (loses hydrogen) forming 2 molecules of pyruvate (3 carbon compound)
End products of glycolysis are:
2 reduced NAD
2 pyruvate
2 ATP
If oxygen is present - 3 carbon pyruvate passes into mitochondria where it is completely oxidised forming CO2 and H2O. If no oxygen is present then 3C pyruvate becomes:
lactate
The LR links glycolysis to the …
krebs cycle
LR -one carbon atom is formed from pyruvate in the form of:
CO2
LR-The remaining 2-carbon molecule combines with coenzyme A to produce:
acetyl coenzyme A
LR-Another oxidation reaction occurs when:
NAD+ collects more hydrogen ions - this forms reduced NAD
LR- no ATP..
is produced in this reaction
LR- for each glucose molecule used in glycolysis:
2 pyruvate molecules are made
LR - but the link reaction uses only the pyruvate molecule, so the link link reaction and the krebs cycle happen…
twice for every glucose molecule, which goes through glycolysis
overall equation for one LR and KC =
pyruvate + NAD + CoA -> acetyl CoA + reduced NAD + CO2
Products of LR are:
for each glucose molecule:
- 2 acetyl coenzyme A (goes to krebs cycle)
- 2 carbon dioxide (released as a waste product)
- 2 reduced NAD (go to electron transport chain)
