Key area 2.1 Flashcards
What is cell metabolism
Sum total of all chemical reactions within a cell
What is a metabollic pathway
Enzyme conrtolled sequence of chemical reactions in the cell
Name the 2 types of metabollic pathways
Catabolic
Anabolic
Describe catabolic
And give an example
Brings about the break down of complex molecules into simplier ones
Releases energy
Protein - Amino acids
Describe anabolic pathways
Brings about the biosynthesis or molecules from smaller ones
Requires energry
Amino acids - proteins
What is the advantage of having a reversible pathway
Allows the cells to regulate the pathway
hat are steps in metabolic pathways regulated by
Enzymes
What is the function of the cell membrane
Allows the entry and exit of substances in the cell
What is the cell membrane made of
Phospholipids and embedded proteins
What is the purpose of having membrane bound compartments in cells
Allows compartmentalisation which means reactions can be kept seperate in cells
What is the advantage to cells of having many small compartments
Higher surface area allows high concentration and high reaction rates
Name and describe the types of proteins found in the membrane
Enzymes: Catalyse a specific reaction
Channel (Pore): Allows specific mols and ions to pass through by passive transport
Carrier (Pump): Binds to specific mols or ions temporarily allowing them to pass by active transport
Structual protein: Help maintain the shape of the cell
How do enzymes speed up chemical reaction
Speed up chemical reactions by lowering activation energy
Bringing substrate close
Explain the induced fit model
- Active sit has a flexible structure
- Active site alters its shape to fit substrate more closely
- This increases the rated reaction as it helps orient the substrate in right way for reaction to occur
State the affinities an enzyme has for a product and substrate
Enzymes have a high affinity for the substrate
Enzyme have a low affinity for the product
What is enzyme co-factor
Molecules needed to make an enzyme more efficient
Describe what is meant by a multi-enzyme complex
A group of enzymes working together to acheive one step in a metabollic pathway
3 ways an enzyme activity can be regulated
- Controlling number of enzymes in a cell
- Keeping reactants in compartments
- Changing enzyme shape most effective
What is an inhibitor
Reduces rate of reaction by interfering with enzyme in some way
Name the types of inhibition
- Competitive
- Non competitive
- Feedback
Describe how competitive inhibiton works
- Similar shape to substrate
- Binds to enzyme active site but remain inactive
- Less substrate can bind to enzyme
- Temporary as increasing substrate concentration will outnumber inhibitors
Describe non competitive inhibiton
- Binds to substrate only other site not active site
- Causes whole enzyme to change structure
- No longer binds with specific substrate
- May or may not be temporary as these inhibitors do not compete
Describe how feedback initiation works
The product binds to an enzyme earlier on in the pathway
It’s bind to another site than the active site
This changes the shape on the enzyme meaning it can no longer bind to its specific substrate
Describe how feedback initiation works
The product binds to an enzyme earlier on in the pathway
It’s bind to another site than the active site
This changes the shape on the enzyme meaning it can no longer bind to its specific substrate
