Mr McAlonan - Enzymes

Question 1

What are enzymes

Answer 1

Enzymes are biological catalysts

Question 2

What are enzymes made from

Answer 2

Enzymes are made from globular proteins

Question 3

What do enzymes do

Answer 3

Enzymes interact with substrate molecules which caused him to react with much faster rates without the need for a harsh environment. Without enzymes many of the processes necessary would not be possible. Enzymes lower the activation energy of metabolic reactions in living organisms

Question 4

What are the chemical reactions required for growth and metabolic pathways

Answer 4

The chemical reactions required for growth anabolic (Building up) reactions and they are all catalysed by enzymes. Metabolic pathways consist of many catabolic (breaking down) reactions. Catabolic reactions are also catalysed by enzymes

Question 5

How are large organic molecules obtained and how are they broken down

Answer 5

Large organic molecules are obtained from the digestive of food which are made up of even larger organic molecules e.g. starch. Digestion is also catalysed by a range of enzymes

Question 6

What is metabolism

Answer 6

Metabolism is the sum of all the different reactions and reaction pathway happening as a result of the control and order imposed by enzymes

Question 7

What impacts the reaction speeds of each enzyme

Answer 7

Reaction speeds are dependent on the conditions such as temperature, pressure and pH. Enzymes can only increase the rate of reaction up to certain point this is called the Vmax (maximum initial velocity or rate of the enzyme catalysed reaction)

Question 8

How do reactions occur with enzymes

Answer 8

Enzyme reactions take place by Molecules in a solvent move and randomly collide with an enzyme for a reaction to happen to my kids need to collide in the right orientation. A higher temperature or increased pressure can increase the likelihood of a random collection and overall increase the rate of reaction

Question 9

There are many organic molecules that need to be catalysed by an enzyme how does this happen

Answer 9

One enzyme type has to Catalyse one specific organic molecule and so there are thousands of enzymes in any given cell. This is termed as specificity For the enzymes.

Question 10

How does the reaction take place

Answer 10

Energy is required for the reaction to take place this is called activation energy. Sometimes the amount of energy needed is so large that it prevents the reaction from taking place under normal conditions. Enzymes help the molecules collide successfully and therefore reduce the activation energy required.

Question 11

What are two hypotheses and how enzymes react

Answer 11

The lock and key hypothesis and the induced fit hypothesis

Question 12

What is the lock and key hypothesis

Answer 12

The lock and key hypothesis is the enzyme has a specific shape and the substrate also has a specific shape that fits the active site. This is then how the lock is the enzyme and the key is the substrate and they fit together. Once the substrate enters the active site of the enzyme that breaks up the substrate into two products and leaving the enzyme active site unchanged and this enzyme is then able to take place in another reaction.The R – group within the active site of the enzyme also interacts with the substrate this then forms tertiary bonds and put a strain on the substrate which then helps the reaction to take place

Question 13

Is the induced fit hypothesis

Answer 13

In the induced fit hypothesis the active site changes slightly as the substrate enters. The induced fit hypothesis is a modified version of the lock and key hypothesis. The initial interaction between the enzymes in the substrate is relatively weak, he is weak interaction is rapidly induce changes in the enzymes tertiary structure that strengthen binding. Putting strain on the substrate molecule is then we can particular bond of bonds in the substrate, therefore lowering the activation energy for the reaction to take place.

Question 14

What are Intracellular enzymes

Answer 14

Intracellular enzymes have an essential role in the structure and function of cells. The synthesis of polymers from one of those e.g. making polysaccharides from glucose requires enzymes and therefore enzymes that act in a cell are called intracellular enzymes.

Question 15

What are extracellular enzymes

Answer 15

Extracellular enzymes have to supply the cells with Substrate (raw materials) to make products needed by organisms. There is a high demand in the cells that need a constant supply of nutrients which are necessary for survival and growth these are present in the diet or environment of the organism. The nutrients are often in forms of polymers such as proteins and polysaccharides these molecules can’t enter the cell answer therefore have to be broken down into smaller components before entering the cell. To breakdown the nutrients before enters the cell, enzymes have to be released from the cell in a process called digestion and therefore they are extracellular enzymes because they work outside to cell.

Question 16

How do you single cell organisms use extracellular enzymes

Answer 16

Single cell organisms such as bacteria and yeast they have to release enzymes into their immediate environment. The enzymes then break down large molecules such as proteins and smaller medicals produced such as amino acids and glucose are then absorbed into the cell

Question 17

How do you multicellular organisms use extracellular enzymes

Answer 17

Multicellular organisms eat food to gain the nutrients and then the food is broken down in the digestive system the enzymes are released to break down the large molecules into smaller molecules to then be absorbed into the bloodstream then from there or transported around the body to be used as substrate in cellular reactions. Examples of extracellular enzymes involved in digestion in humans are amylase and trypsin.

Question 18

How does the digestions of starch take place

Answer 18

The digestion of starch begins at the mouth and continues into the small intestine. The starch is digested into steps involving two different enzymes. Different enzymes are needed because the Enzymes only catalyse one specific reaction.

1. Starch polymers are particularly broken down into maltose, which is a disaccharide. The enzyme involved in this stage is called amylose. Amylase is produced by the salivary glands and the pancreas. It is released in saliva in the mouth, and the pancreatic juice into this small intestine.
2. Maltose is broken down into glucose, which is a monosaccharide. The enzymes involved in this stage is called Maltese. Maltese is present in a small intestine. The glucose is then small enough to be absorbed by the cell lining in the digestive system and is subsequently absorbed into the bloodstream.

Question 19

How does digestion of proteins happen

Answer 19

Trypsin is a protease, a type of enzyme that catalyse is the digestion of proteins into smaller peptides, which can then be broken down further into amino acids by other protease. Trypsin is produced in the pancreas and released within the pancreatic juice into the small intestine, where it also acts on protease. The amino acids are absorbed by the lining in the digestive system and then absorbed into the bloodstream.

Question 20

What is a Competitive inhibitors

Answer 20

A competitive inhibitor molecules have a similar shape to that of a substrate molecule. They compete with the substrate molecules to bind to the active site, but no reaction takes place. Instead they block the active site so no substrate molecule can fit in. How much the enzyme is inhibited depends on the relative concentrations of the inhibitor and substrate. If there is a high concentration of inhibitor, it will take up nearly all the active site and hardly any of the substrate will get into the enzyme. But if there is a high concentration of substrate, then the substrate chances of getting an active site before the inhibitor increase. So increasing the concentration of substrate will increase the rate of reaction up to a certain point.

Question 21

What is a non-competitive inhibitor

Answer 21

A non-competitive inhibitor molecule binds the enzyme away from the active site the site they bind to his nose the enzymes allosteric site. This causes the active Site to change shape so the substrate molecule can no longer bind to it. Non-competitive inhibitor molecules don’t compete with the substrate molecules to bind to the active site because there are a different shape Increasing the concentration of substrate won’t make any difference the enzyme activity will still be inhibited.

Question 22

How does temperature affect the rate of reaction for an enzyme

Answer 22

The increasing temperature therefore increases the amount of kinetic energy the substrates and enzymes have this therefore increases the amount of random collisions between the active site and the substrate however the temperature increases up to certain point for the enzymes V-max and then after a certain point in increased temperature (around 40°) the active site will denature and the enzyme will no longer be able to be used.

Question 23

How does pH level affect the rate of reaction for an enzyme

Answer 23

There are different optimum pH levels for different enzymes. Enzymes found in the mouse have a different pH level than in the stomach as in the stomach and more effective around high acidity levels than enzymes found in the mouth were there closer to a balance PH

Question 24

What is a cofactor

Answer 24

A cofactor can be an Inorganic molecules or irons. They work by helping the enzyme and substrate bind together. However they do not directly participate in the reaction and therefore is not used up for a change of shape happens to the cofactor. Examples include chloride is an inorganic cofactors for the enzyme amylase

Question 25

What is a co-enzyme

Answer 25

A co-enzyme is an organic cofactor they partake in the reaction and are used like a second substrate. They act like Harry is moving chemical groups between different enzymes they are continuously changed and recycled in this process. E.g. vitamins are often sources of enzymes coenzyme NAD is derived from vitamin B3.

Question 26

What is a prosthetic group

Answer 26

A prosthetic group is tightly bound to the enzyme oh and form a permanent feature of the protein. E.g. zinc ion for carbonic anhydraseCall Mum and Enzo necessary for the metabolism of carbon dioxide

Question 27

Describe the use of coenzymes in enzyme mediated reactions

Answer 27

: Enzymes are small, non-protein molecules that bind to an enzyme at the same time as substrate to facilitate the reaction and insure reactions occur in the correct order. They are altered by the reaction and recycle for reuse. They can accept and donate electrons and protons or groups of molecules.