module 4 Flashcards
What is respiration
Process whereby energy stored on complex organic molecules (carbs fats and priteind) is used to make ATP and happens in living cells
What is energy
The ability to do work
What is ATP
A phosphorylated nucleotide and is the universal energy currency
What is potential and kinetic energy
And what molecules have them?
Potential is stored energy
Organic molecules
Kinetic energy is energy if movement
Moving molecules
3 things about energy
Can’t be created or destroyed but can be converted
Measured in joules or kilo joules
Has many forms
Why do we need energy
For biological processes/metabolism
What are anabolic and catabolic reaction
Anabolic
Smaller molecules into large ones
Catabolic
Large molecules broken down to smaller ones4
7 metabolic processes that need energy.
Active transport
Secretion
Endocytosis
Synthesis of large molecules from smaller ones
Dna replication and synthesis of organelles before cell divides
Movement
Activation of chemicals
Read book to explain processes that use energy
Just saying
Why us it useful for catabolic reaction so release energy
Cz metabolic reactions are controlled by enzymes. Organisms need to maintain a suitable temp that allows enzyme action to proceed at a speed that will sustain life
Where does energy come from
Photoautotrophs use sunlight energy in photosynthesis to make large organic molecules that contain chemical potential energy Which they and consumers and decomposer can then use
What does respiration do with the energy
It releases it
What happens when energy is released by respiration
It phosphorylate ADP making ATP
This phosphorylation also transfers energy to the ATP molecule
Talk about the role of ATP
A phosphorylated nucleotide
In bith eukaryotic and prokaryotic
Molecule consists of adenosine (adenine and ribose sugar) plus 3 phosphate groups
Can be hydrolysed to ADP and Pi releasing energy
What does it mean that ATP can be hydrolysed to release energy
Energy is immediately available to cells in small manageable amounts that will not damage the cell and will not be wasted
Why is it you only have 5g of ATP at any given time
Cz ATP is continually being hydrolysed and resynthesised
An example of what the hydrolysis of ATP is coupled with a synthesis reaction
Dna replication
Protein synthesis
Synthesis reaction require energy, where do they get this energy from
Energy released from ATP hydrolysis
4 stages if respiration of glucose
Glycolysis
The link reaction
Krebs cycle
Oxidative phosphorylation
Talk about glycolysis
Happens in cytoplasm of all cells
Doesn’t need oxygen and can take place in aerobic or anaerobic conditions
Glucose 6C is broken down to 2 pyruvate molecules 3C
Talk about the link reaction
Happens in the matrix of mitochondria
Pyruvate dehydrogenated and decarboxylated
Pyruvate then converted to acetate
Talk about Krebs cycle
Take a place in matric of mitochondria
Acetate dehydrogenated and decarboxylated
Talk about oxidative phosphorylation
Takes place on cristae of mitochondria
This is where ADP is phosphorylated to ATP
What’s to say about the last 3 stages
Only take place under aerobic conditions
Under anaerobic conditions pyruvate is converted toeither ethanol or lactate
Why are coenzymes needed
Because when hydrogen atoms are removed from substrate molecules in oxidation reactions, the reactions are catalysed by dehydrogenase enzymes
And enzyme aran et good at catalysing oxidation or reduction reactions
So coenzymes are needed to help for respiration
2 coenzyme examples x
NAD
coenzyme a
What happens when a hydrogen atom us combined with a coenzyme such as nad
Carry the hydrogen atoms which can later be split into hydrogen ions and electrons, to the cristae
Here they’ll be involved in the process of oxidative phosphorylation which produces a lot of ATP
Delivery of the hydrogens to the cristae repaid uses the coenzymes so they can combine with more hydrogen atoms from the first 3 stages of respiration
Nad is an organic non protein molecule
Made if 2 linked nucleotides
Made in the body from vitamin b3
One nucleotide Contains the nitrigenous base adenine. The other contains a nicotinamide ring that can accept hydrogen atoms each of which can later be split into a hydrogen. Ion and an electron
Just saying
What happens when a molecule of nad accepts 2 hydrogen atoms with their electrons
It becomes reduced
Opposite is oxidised
When does nad operate
During glycolysis
Link reaction
Krebs cycle
And during anaerobic ethanol and lactate pathways
What is coenzyme a made up of
A b group vitamin
Ribose and adenine or adenosine
The phosphate groups
And cysteine and amino acid
Function of coenzyme a
Carry ethanoate (acetate) groups, made from pyruvate during the link reaction , onto Krebs cycle.
Can also carry acetate groups that have been made from fatty acids or from some amino acids onto Krebs cycle.
What I’d oxidation
Reactions involve loss of electrons
What is reduction
Reactions involve additions of electrons
What is glycolysis
A metabolic pathway where each glucose molecule is broken down to 2 molecules of pyruvate
Occurs on cytoplasm of all living cells and is common to anaerobic and aerobic respiration
What is Hexose
Sugars have six carbon atoms in each molecule
What is hydrolysis
Breaking down of large molecules to smaller ones by addition if water
Wat is triose
Sugars that have 3 carbon atoms in each molecule
Glycolysis occur in eukaryotic or pro
Both
How many relations does the glycolysis sequence have
What else
10
Each catalysed by a different enzyme
What are the 4 stages of glycolysis
Phosphorylation
Splitting of Hexose 1,6-bisphosphate
Oxidation of triode phosphate
Conversion of triose phosphate to pyruvate
Talk about phosphorylation stage in term so glycolysis
One ATP is hydrolysed and the phosphate group releases is attached to the glucose molecule at carbon 6
Glucose 6 phosphate is changed to fructose 6 phosphate
Another ATP molecules is hydrolysed and phosphate group attached to carbon 1 though
Sugar is now called fructose 1,6-bisphosphate
The energy from the hydrolysed ATP molecules activates the Hexose sugar and prevents it from being transported out if the cell
We can refer to the activated, phosphorylated sugar as Hexose 1,6 bisphosphate
The stage uses 2 ATP molecules for each glucose molecule
What needs to happen to glucose before glycolysis AND why
It’s molecules need to be activated before they can split into 2
This is cz it’s a Hexose sugar and it’s molecules are stable
Talk about stage 2
Splitting of Hexose 1,6-bisphosphate
Each molecule of Hexose 1,6-bisphosphate is split into 2 molecules of triose phosphate
Talk about stage 3 oxidation of triose phosphate
3rd stage is anaerobic but involves oxidation
2 hydrogen atoms with their electrons are removed from the triose phosphate
This involves dehydrogenase enzymes
These enzymes are aided by coenzyme Nad which is a hydrogen acceptor
Nad combines with hydrogen atoms and becomes reduced nad
So 2 molecules of nad are reduced per molecule of glucose
2 molecules of ATP are also formed (called substrate level phosphorylation)
Tall about stage 4
Conversion of triose phosphate to pyruvate
4 enzyme catalysed reactions convert each triose phosphate molecule to a molecule of pyruvate
Pyruvate is also a 3 carbon compound
Another 2 molecules of ADP are phosphorylated to two molecules of ATP like third stage
What are the products of glycolysis
2 molecules of ATP. 4 made but 2 were used to kick start process
2 molecules of reduced nad
These will carry hydrogen atoms to the inner mitochondrial membranes and be used to generate more ATP during oxidative phosphorylation
2 pyruvate molecules
Actively transported into the mitochondrial matrix for the next stage of aerobic respiration
In the absence of oxygen it will be changed in the cytoplasm to lactate or ethanol 6
Examiner tip Learn stages of glycolysis where ATP is used ATP is produced Nad is reduced
Just saying
