metabolism Flashcards
what procsses do we need energy for?
muscle contraction
active transport
synthesis of complex biomolecules from simple precursors
what is the definition of thermodyanmics simple
energy cannot be created or destroyed, but it can be converted from one form to another.
Heterotrophy
Energy and volume are obtained from other organisms e.g. mammals
Autotrophy
Energy derived from sunlight and volume for CO2 in the atmosphere e.g. plants.
Chemotrophs
Energy from chemical redox reactions
Chemoorganotrophs
Extract energy from organic compounds by oxidation
what is considered a healthy diet
balance between carbohydrate, protein and fats. Energy intake and energy use also need to be balanced.
what things increase heart disease
. Diets high in saturated lipids or cholesterol
what type of diet can increase insulin resistance and type 2 dibeates
Diets high in processed carbohydrate
what does obesity increase
increases the risk of both heart disease and diabetes
what are the functions of metabolism 1/2
`Synthesis of precursors e.g. amino acids, Fatty acids, carbohydrates, proteins nucleic acids.
what are the functions of metabolism 2/2`
Provision of energy. For synthesis, mechanical work, heat production, ion pumps etc.
Metabolic pathways are a series of reactions They may be:
Linear
Divergent
Convergent
describe central metabolic pathways
Few in number
Highly conserved throughout nature
descibe the structure of atp
3phosopahte molecules attached to ribose and adenine
what are the bonds on atp
it contains 2 phosphoanhydride bonds on its triphosphate unit
what is needed to synthesises atp
oxygen
to convert atp into adp what needs to happen
MOTION
active transport
biosyntheses
to convert adp into atp what do you need to do
oxidation of fuel molecules or photosyntehsis
atp production: Substrate level phosphorylation
Transfer of phosphoryl group from metabolites with high-phosphoryl transfer potential to ADP producing ATP
ATP production :Oxidative phosphorylation
Process of ATP formation as a result of transfer of electrons from fuels via electron carriers (NADH or FADH2) to the final electron acceptor oxygen
what is creatine made from in our body
Synthesis from glycine, arginine and methionine in liver
what is hexokinase?
a 6 carbon phosphorylating enzyme
how is glucose 6 phosphate formed
Glucose 6-phosphate is trapped in cells by its negative charge and is destabilized by a phosphoryl group for metabolic breakdown. The reaction strongly favors its formation, making it nearly irreversible.
what is Phosphoglucose isomerase
isomerase – convert from one isomer (glucose) to another (fructose)
Phosphofructokinase
enzyme in glycolsis
summarise Phosphofructokinase
Kinase – phosphorlyating enzyme
Phosphofructo – fructose with a phosphoryl group attached.
Key regulatory enzyme in glycoloysis
summarise alodlase
Named from the reverse reaction which is an aldol condensation.
6 carbon sugar split into two 3 carbon sugars.
summarise triose phosphate isomerase
isomerase – convert from one isomer (dihydroxyacetone phosphate) to another (glyceraldehyde phophate).
GAP is used directly in glycolysis whereas DHAP is not.
Isomerase converts DHAP (ketose) to GAP (aldose) for use in glycoloysis
summarse energy transformation>
Glucose has been converted to glyceraldehyde 3-phosphate but no ATP has been synthesised.
Glyceraldehyde 3-phosphate dehydrogenase
dehydrogenase – transfer “high energy” electrons from complex organic molecule to NAD+ to form NADH
Phosphoglycerate kinase
catalyzes the transfer of a phosphate group from 1,3-bisphosphoglycerate to ADP, forming ATP and 3-phosphoglycerate.
what is enolase
Enolase – formation of an enol (phophoenolpyruvate)
ATP synthesis and glycolysis- final products
The net production of ATP in glycolysis is 2 ATP molecules.
what happens to pyruvate when it undergoes aerobic metabolism
it forms acertl coa
what happens to pyruvate when it undergoes anaerobic metabolism
Lactic acid (lactate) and
Ethanol is forned
METABOLIC FATE OF PYRUVATE
During glycolysis, NAD+ is converted to NADH. If the concentration of NAD+ decreases, glycolysis halts.
With oxygen, electrons from NADH move through the electron transport chain to oxygen, generating water, ATP, and regenerating NAD+.
Without oxygen, electrons from NADH are transferred to pyruvate, producing lactate or ethanol and restoring NAD+.
how is lactic acid produced in anaerboic activity
NADH is oxidised by transfer of electrons to pyruvate to form lactic acid
Lactic acid production during anaerobic activity
Lactic acid breaks down into lactate and hydrogen ions,
lowering pH and potentially causing muscle pain and reduced muscle function.
This can lead to decreased activity. The body can recover from the “oxygen debt” by converting lactate back into glucose in the liver, a process which generally takes about 30 minutes.
Ethanol production in yeast cells
In aerobic conditions yeast break glucose down to carbon dioxide and water.
Yeast cells produce ethanol during anaerobic metabolism.
Gluconeogenesis
Glucose formation from noncarbohydrate precursors.
what is the daily requimrent for glucose?
160g (Brain 120g)
gluconegenosis
The liver is the primary organ for gluconeogenesis, which is essential for maintaining blood glucose levels for use by the brain and muscles
. This process synthesizes glucose from pyruvate,
Precursors are either converted to pyruvate or enter the gluconeogenesis pathway at intermediates such as oxaloacetate or dihydroxyacetone phosphate (DHAP).
lactate as a pre cursour
Skeletal muscle when glycolysis exceeds oxidative metabolism
amino acids as pre cursour
Diet or during starvation (Muscle breakdown)
glycerol as pre cursour
Hydrolysis of TAG yeilds glycerol and fatty acids
summarise gluconeogensis
In mammals, gluconeogenesis mainly occurs in the liver and kidneys to produce glucose for the brain, muscles, and red blood cells
Three irreversible steps of glycolysis are bypassed by gluconeogenic enzymes
-Conversion of Pyruvate to PEP via oxaloacetate
-dephosphorylation of F 1,6-bisP
-dephosphorylation of G 6-P
Formation of one molecule of glucose from pyruvate is energetically expensive requiring 4ATP, 2GTP and 2NADH
Entry of fructose and galactose into glycolysis
fructose and galactose play significant roles in human diets as they are commonly found in various foods
what happens to galactose and fructose in glycolsis
Galactose and fructose are converted into intermediates of glycolysis
Galactose metabolism
Galactose is converterted to glucose 6-phosphate
Fructose metabolism
Fructose is converted, by hexokinase, to fructose 6-phosphate.
ORRRRR
Fructose is metabolised, in the fructose 1-phosphate pathway, to DHAP and GAP
Inherited defects in metabolism
Lactose intolerance
Fructose intolerance
what causes fructosuria
fructokinase enzyme
Fructose intolerance
- lack of fructose-1-phosphate aldolase
Inorganic phosphate (Pi) is consumed in the production of fructose-1-phosphate, which can disrupt the liver’s ability to generate ATP from ADP. This leads to the malfunctioning of ATP-dependent ion channels, causing cells to swell.
where does the krebs cycle occur?
Takes place in the matrix of the mitochondria
what happens in the krebs cycle
Acetyl CoA converted into 2 CO2, 8 high energy electrons and GTP
High energy electrons are transferred to NADH and FADH2
Electrons are then transferred to oxygen in oxidative phosphorylation to produce ATP
what does the kreb cycle act as
act as a source of biosynthetic precursors
what is Oxidative Phosphorylation
The process by which ATP is formed as a result of transfer of electrons form NADH or FADH2 to oxygen
electron carrriers
NADH and FADH2 are the major electron carriers in the oxidation of fuel molecules.
what is oxidative phosphorylation composed off
Electron Transport
ATP synthesis
Electron Transport
The electron transport chain consists of a series of oxidation/reduction (redox) couples.
These redox couples interact to carry out the overall reaction:-
2H2 + O2 2H2O
what is in the electron transport chain?
There are three protein complexes and two mobile electron carriers.
Energy is released during each of the oxidation/reduction reactions.
why os cynaide dangerous
Cyanide inhibits cellular respiration by binding to cytochrome oxidase, preventing electron transport. As a treatment, nitrite is used to convert hemoglobin to a form that competes with cytochrome oxidase for cyanide, aiding in the removal of the toxin.
what is chemiosmotic hypothesis
Electron transport and ATP synthesis coupled by a proton gradient
what is the evidence to support chemiosmotic hypothesis
A proton gradient can be measured
ATP synthesised if gradient created
summarise how atp is generated
ATP is produced in cells through a process where electrons are transferred from NADH or FADH2 to oxygen through a series of reactions in the electron transport chain.
The energy from electron transfer is used to pump protons out of the mitochondrial matrix, creating a proton motive force.
Finally, ATP is synthesized by the enzyme ATP synthase as protons flow back into the mitochondrial matrix through this enzyme.
how much atp does OP create
26
how much atp does the glycolsis and krebs create
2 and 2
