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45 Cards in this Set

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Why do we need energy?

Active transport.


Secretion.


Endocytosis.


Synthesis of large molecules.


Replication of DNA.


Synthesis of organelles.


Movement.


Activation of chemicals.

What are anabolic reactions?

Where larger molecules are hydrolysed to make smaller molecules.

What is the role of ATP?

To provide an immediate, but manageable, source of energy for biological processes.

What are the four Stages of respiration?

Glycolysis.


Link reaction.


Krebs cycle.


Oxidative phosphorylation.

Why are coenzymes needed?

To help the oxidation and reduction enzymes.

What is NAD?

An organic non-protein molecule that helps dehydrogenase enzymes carry out oxidation reactions.

When does NAD become reduced?

When it has accepted two hydrogen atoms with their electrons.

What does Coenzyme A do?

Carry ethanoate and other acetate groups onto the krebs cycle.

What is glycolysis?

A metabolic pathway where each glucose molecule is broken down to two molecules of pyruvate.

What are the four stages of glycolysis?

Phosphorylation.


Splitting of hexose-1,6-bisphosphate.


Oxidation of triose phosphate.


Conversion of triose phosphate to pyruvate.

What happens in stage one of glycolysis?

ATP is hydrolysed and a photphate group attached to a glucose molecule.


A glucose-6-phospate is formed. That is converted into frusctose-1-phosphate.


Another ATP is hydrolysed and fructose-1,6-bisphosphate is formed. This hexose sugar becomes activated and connot leave the cell.

What happens in stage two of glycolysis?

Each molecule of hexose bisphosphate is split into two triose phosphates.

What happens in stage three of glycolysis?

Two hydrogen atoms are removed from each triose phosphate molecule.


The coenzyme NAD helps the dehydrogenase enzymes and becomes reduced NAD.


Two molecules of ATP are formed.

What happens in stage four of glycolysis?

Each triose phosphate molecule is converted into a molecue of pyruvate.


Two molecules of ATP are formed through phosphorylation.

What are the products of glycolysis?

Two molecules of ATP.


Two molecules of reduced NAD.


Two molecules of pyruvate.

Three things about energy?

It can only be converted from one form to another, cannot be created or destroyed.


Measured in joules or kilojoules.


Has many forms.

What are mitochondria?

Organelles found in eukaryote cells. They are the site of the link reaction, krebs cycle and oxidative phosphorylation.

What is the ultrastructure of mitochondria?

An envelope consisting of an inner and outer membrane.


The outer membrane is smooth and the inner membrane is folded into many cristae.


The matrix is enclosed by the inner membrane.

Where does energy come from?

Sunlight and respiration.

What is respiration?

The process whereby energy stored in complex organic molecules is used to make ATP.


What is anaerobic respiration?

The release of energy from substrates in the absence of oxygen.

What does the matrix of the mitochondria contain?

Enzymes.


Coenzyme NAD.


Oxaloacetate.


Mitochondrial DNA.


Mitochondrial ribosomes.

What are some features of the inner membrane?

Impermeable to most small ions.


Folded into many cristae for a large surface area.


Has many electron carriers and ATP synthase enzymes embedded in it.

What is chemiosmosis?

When protons flow down a proton gradient through the ATP synthase enzymes into the matrix.

What is the shape and size of mitochondria?

Rod-shaped or thread-like.


0.5-1.0 micrometers in diameter.


2-5 micrometers long (can be longer in athletes).

How are mitochondria distributed?

More metabolically active cells have more mitochondria with densely packed cristae.


What is the equation that summarised the link reaction?

2CoA+2pyruvate + 2NAD+ = 2CO2 + 2 reduced NAD + 2 acetyl CoA

What happens during the krebs cycle?

Acetate binds with oxaloacetate to form citrate. That is dehydrogenated and decarboxylated to form a 5C compound. The 5C compound is decarboxylated and dehydrogenated to form a 4C compound. This compound is converted into another 4C componud and ATP is produced. Reduced FAD is formed. This compound is converted into another 4C compound which is dehydrogenated to produce oxaloacetate.

What is NADH reductase?

The first electron carrier, a protein complex. NADH - coenzyme Q reductase.

What is oxidative phosphorylation?

The formation of ATP by adding an inorganic phosphate to ADP in the presence of oxygen.

How many turns of the krebs cycle are there per molecule of glucose?

two.

What is the final electron acceptor?

Molecular oxygen.

Why is the theoretical yield of ATP rarely reached?

Some protons leak across the mitochondrial membrane, reducing the proton motive force.


Some ATP produced is used to actively transport pyruvate.


Some ATP is used to bring hydrogen from reduced NAD.

What is peter mitchell's theory?

1961


Chemiosmosis theory.


A build up of hydrogen ions in the matrix forminsg a proton gradient. The flow of ions forms ATP.


Proton motive force.

Why is the theoretical yield of ATP rarely reached?

Some protons leak across the mitochondrial membrane, reducing the proton motive force.


Some ATP produced is used to actively transport pyruvate.


Some ATP is used to bring hydrogen from reduced NAD.

What is some evidence for Chemiosmosis?

The pH in the intermembrane space is lower than the matrix (lower pH means more protons).


Mitochondria placed in alkali solution doesn't synthesis ATP but does when it is placed in acidic solution (acid- provides protons for proton gradient).


Vesicles containing ADP and Pi and ATP synthase only synthesise ATP when a proton gradient is available.


Uncouplers destroy proton gradients and when these are present ATP is not synthesised.

What is the final electron acceptor?

Molecular Oxygen.

How many turns of the krebs cycle are there per molecule of glucose?

two.

What is oxidative phosphorylation?

The formation of ATP by adding an inorganic phosphate to ADP in the presence of oxygen.

What is NADH reductase?

The first electron carrier.


A protein complex.


NADH-coenzyme Q reductase.

What happens during the kerbs cycle?

Oxaloacetate binds to acetate to form citrate.


EDIT

What is the equation that summarised the link reaction?

2CoA+2pyruvate+2NAD+ = 2CO2+2reduced NAD+2acetyl CoA.

What are the steps of lactate fermentation?

Reduced NAD must be reoxidised to NAD+.


Pyruvate accepts hydrogen atoms from reduced NAD.


NAD can now accept more hydogen ions from glucose.


Glycolysis can continue.

What are the two types of energy?

Potential energy and kinetic energy.

State two types of ecological interaction that can occur between different species in a habitat?

Predator/prey


Lynx - hare




Competition for resources.


red squirrel/grey squirrel.