Chapter 16 (Cellular Respiration) Flashcards
What is ATP
- Phosphorylated nucleotide
- Universal energy currency
- Short term energy molecule
- Large molecule so can’t diffuse across cell membranes.
Definition of oxidation?
Removal of hydrogen ions
Addition of oxygen
loss of electrons
definition of Reduction
Addition of hydrogen ions
Removal of oxygen
Gain of electrons
Definition of dehydrogenation
Removal of hydrogen ions
Definition of decarboxylation
Removal of carbon dioxide
Product has one less carbon atom within it.
Definition of phosphorylation
Addition of of a phosphate group
sometimes involves kinase
What is decarboxylase
Enzyme that removes carboxyl group from molecule. (carries out decarboxylation)
by hydrolysis, releasing CO2
Occurs in link reaction and krebs cycle
What is dehydrogenase
Enzyme that removes hydrogen atoms from molecules.
Passes hydrogen atoms to another molecule.
(dehydrogenation reaction)
Occurs in link reaction, krebs cycle and E transport chain.
What is a kinase
Enzyme that adds a phosphate group to a molecule.
Often involves ATP (as phosphate group donor)
What are coenzymes
An additional molecule required by some enzymes to enable their function. (Non-protein organic molecules which bind to enzyme’s active site.)
Required by many dehydrogenases to accept/donate hydrogen atoms removed by the enzyme.
Examples of coenzymes
NAD
FAD
CoA
What does NAD do
Hydrogen carrier produced in body.
Nicotinamide part accepts pair of hydrogen atoms, so NAD becomes red NAD, so it can then donate pair of hydrogen atoms - Becomes oxidised
What does FAD do
Acts as hydrogen carrier, so FAD becomes red FAD when it accepts hydrogen atoms. It becomes oxidised when it donates hydrogen atoms.
What does CoA
Organic molecule consisting of adenosine ( adenine + ribose), 3 phosphates, cysteine and Pantothenic acid ( Vit B)
Carries 2 carbon fragments.
Glycolysis info
NET INCREASE COME BACK TO
In cytosol
each stage requires specific enzyme to increase rate of reaction.
Function - to split glucose (hexose 6C) into 2 trioses (3C)
Input: Glucose, 2ATP, NAD, enzymes
Output: 2 Pyruvate, 4ATP, 2 red.NAD
What is the purpose of ATP
To supply energy to drive metabolic reactions and other processes inside cells
Examples of uses of ATP
Bioluminescence
Endocytosis
Active Transport
Muscle contraction
Spindle fibre formation in mitosis + meiosis
Anabolic reactions, eg, protein synthesis, semi-Conservative replication
Maintenance of internal stable body temperature
BEAMSAM
Properties of ATP
- Small
- Water soluble (easily transported around the cell)
- Easily hydrolysed and reformed
- Bonds between adjacent phosphates are easily broken
Why is ATP called the ‘universal energy currency’
UNIVERSAL
-Found in ALL eukaryotes and prokaryotes
ENERGY CURRENCY
- can be hydrolysed to release small quantities of energy
- ATP ADP + Pi is reversible
- Terminal phosphate group is hydrolysed to release energy
- Energy can be passed to other molecules
- It has a high turnover and acts as an immediate energy donor.
How is ATP formed
During respiration (both aerobic and anaerobic) by the phosphorylation of ADP
How is ATP used
Hydrolysed to release energy that is then used in metabolic reactions inside ALL living cells.
Benefit of the hydrolysis of ATP
Enables energy to be released in small quantities
If all the chemical potential energy from glucose was released in one go, this would release lots of heat which would denature enzymes and cause cell metabolism to stop.
What is the role of a phosphatase
CHECK SPELLING
Responsible for removing a phosphate from a protein
What is substrate-level phosphorylation
Direct phosphorylation of ADP with an inorganic phosphate
does not involve electron transport chain
accounts for 10% of ATP production in aerobic respiration.
What is oxidative phosphorylation
CHECK WHAT THEY WANT FOR THIS ON!!!
ATP is generates from the oxidation of red. NAD and red. FAD, and the subsequent transfer of electrons and pumping of protons.
The movement of electrons down an electron transport chain and ATPSynthase and Chemiosmosis.
(process of oxidation in a series of redox reactions)
Benefits of cristae in mitochondria
Inner membrane folded into cristae
Inc SA to inc no. of electron transport carrier proteins, to inc pumping of protons into the intermembrane space, inc chemiosmosis, inc rate of ATP production
Impermeable to protons
what does the matrix of mitochondria do
- contains enzymes for LR + KC
- contains enzymes for oxidation of fatty acids
- contains lipid droplets
- contains DNA plasmid
What does the plasmid do in mitochondria
Has genes that code of proteins in the ETC
Has genes that code for proteins required to make mitochondrial ribosomes.