Module 2 - Enzymes Flashcards
What is an active site?
an indented area on the surface of an enzyme molecule, with a shape that is complementary to the shape of the substrate molecule.
What is a catalyst?
chemical the speeds up the rate of the reaction and remains unchanged and reusable at the end of the reaction
What is extracellular?
outside of the cell
what is intracellular?
inside of the cell
What is metabolism?
the chemical reactions that take place inside living cells/organisms
what is a product?
a molecule that produces from substrate molecules, by an enzyme catalyzed reaction
what is a substrate?
a molecule that is altered by en enzyme - catalysed reaction
what is an enzyme?
Enzymes are biological catalysts because they speed up metabolic reactions in living organisms.
Can enzymes be used again and again?
Yes, they remain unchanged
Do you need a lot of enzymes to produce a large amount of substrate?
No, a small number of enzymes molecules can convert a large number of substrate molecules into a product per second
what is a turnover number of an enzyme?
the amount of substrate converted of an enzyme
advantages of enzymes?
- they function well in conditions that sustain life.
- they are more specific - usually one enzyme catalyses one specific reaction
What structure does enzymes have?
- they are proteins with a tertiary or quaternary structure
How is the enzyme structure determined?
determined by the sequence of amino acids in the primary protein structure, which they twists and folds in a specific way.
What is different about each amino acid?
- they have different R-groups which determines how they fold
Why is the active shape of the enzyme important?
As the active site will be complementary to the shape of on type of substrate
what happens when the enzyme has kinetic energy?
the enzymes and the substrate randomly collide with each other
what do the enzymes do to the activation energy?
- they reduce the activation energy.
- chemical reactions need to the energy to start them
An example of activation energy can be provided?
It can be provided by heat
Why can the temperature not be raised to high?
The proteins will denature and the lipid structure in cell membrane will fall apart
What is an anabolic reaction?
- If 2 substrates join to form a product, the enzymes hold the 2 molecules close together at the active site
- the necessary bonds can then join together
what is a catabolic reaction?
- if 1 substrate needs to break down into 2 productsm the active site holds the substrate in the correct positions to put a strain on certain bonds
- these then break, giving 2 products
an example of an intracellular enzyme?
catalase which breaks down hydrogen peroxide
what is a metabolic pathway?
when a lot of enzyme catalysed reactions inside the cell do not occur in isolation, they are part of a series of reactions
what are metabolites?
all of the substrate and products
what are extracellular enzymes?
These are secreted out of the cell to act somewhere else
what is an example of an extracellular enzyme?
Digestive enzymes
what do salivary amylase enzymes break down?
breaks down starches into sugar
what does the enzyme pepsin do?
digests proteins found ingested food
what does the enzyme lactase do?
breaks down lactose into smaller sugars (glucose and galactose)
what does the enzyme maltose do?
converts maltose into glucose
what are decomposers?
they are bacteria and fungi which live on dead organic matter, digesting large organic molecules into smaller ones - which they absorb for their own nutrition
what is the lock and key model?
- the enzyme has an active site
- the substrate shape fits into the active site like a key fits into a lock
- this is complementary shape on the substrate
what is the induced fir model ?
- The enzyme and its active site (and sometimes the substrate) can change shape slightly as the substrate molecule enters the enzyme
- These changes in shape are known as conformational changes
- The conformational changes ensure an ideal binding arrangement between the enzyme and substrate is achieved
- his maximises the ability of the enzyme to catalyse the reaction
