enzymes

Question 1

enzymes definition

Answer 1

biological substances (catalyst)
- usually protein molecules made by living cells

Question 2

catalyst

Answer 2

• speeds up a chemical reaction without itself being chemically changed at the end of the reaction

Question 3

enzymes use in human body

Answer 3

• catalyse a vast number of chemical reactions at temperature suitable for living organisms

Question 4

metabolism definition

Answer 4

• chemical reaction that occur in the cells
• involves bond breaking and bond forming

Question 5

types of hydrolase

Answer 5

• carbohydrase
• protease
• lipase

Question 6

carbohydrase

Answer 6

• digests carbohydrates
  hydrolysis of glycosidic bonds
• salivary amylase in the mouth
• pancreatic amylase in the pancreas
• cellulase digest cellulose

Question 7

protease

Answer 7

digests proteins
- hydrolysis of peptide bonds
- pepsin in the stomach

Question 8

lipase

Answer 8

digests lipids
- hydrolysis of ester bonds
- lipase in pancreatic juice

Question 9

enzymes in and out of cell

Answer 9

intracellular enzymes
extracellular enzymes

Question 10

intracellular enzymes

Answer 10

• in the cytosol/nucleus
• attached to the plasmsa membrane
• inside membranous organelles (mitochondria, chloroplast…)
• attached to the membrane of organelles

Question 11

extracellular enzymes

Answer 11

• enzymes that are produced in the cell but packaged to be secreted from the cell and work externally

Question 12

substrate definition

Answer 12

chemical which an enzyme work on

Question 13

one: E+S

Answer 13

• brief and reversible
• no covalent bond formation
• proximity of the enzyme with the substrate in the complex greatly increases the chances of a reaction occurring

Question 14

two: ES

Answer 14

• enzyme and substrate are in random motion
• substrate must collide with the active site of the enzyme at the correct orientation and with sufficient energy to form the ES complex
• short livid
• faster the speed of reaction, the more ES complexes are formed per unit time

Question 15

three: EP

Answer 15

• after enzymatic reaction, ES complex is converted to EP complex
• short lived

Question 16

four: E + P

Answer 16

• EP complex dissociates to form enzyme and product
• enzyme remains unchanged at the end of the reaction and if free to interact with other substrate molevules

Question 17

enzyme pathway

Answer 17

• binding of substrate to enzyme forms an enzyme -substrate complex
• conversion of ES to the enzyme product complex (EP)
• release of product P from EP, to yield free
• ES E+S is an equilibrium bacause when collision partners form an activitated comple. they might not go on and form products
• might not go on and form products, may fall apart

Question 18

metabolism types

Answer 18

anabolic reaction
cataobolic

Question 19

anabolic (def)

Answer 19

• use small simpler molecules to synthesise complex substances
• uses energy harnessed from catabolic activities

Question 20

catabolic

Answer 20

• breaking down complex good substances into sall simpler molecules
• generate a useful form of energy for the cell

Question 21

anabolic reaction

Answer 21

• cells build up/synthesize complex substances from simpler ones
  eg: aminor acids taken into cells may be used to build proteins
• cytoplasm contains a special enzyme to catalyse such reaction

Question 22

catabolic reaction

Answer 22

• cells break down complex substance to simple substance
• in cell respiration, glucose is broken down to release energy and form carbon dioxide and water
• hydrogen peroxide is sometimes produced during chemical reaciton in the cellss

Question 23

slide 16-18

Question 24

enzyme properties

Answer 24

1. globular proteins
2. enzymes are coded for DNA
   . enzymes are highly efficient
3. enzymes are highly specific
4. catalyzed reaction is reversible
5. enzyme activites are affected by multiple factors
6. enzyme incr. rate of reaction by decr energy activation of reaction

Question 25

function 1: globular proteins

Answer 25

- soluble in water - due to hydrophilic R groups of aminor acid residues on the exterior surface of the enzyme molecules - involved in metabolic reactions

Question 26

function 2: enzymes are coded for by DNA

Answer 26

- gene codes for proteins including enzymes - cells which do not have a gene wich codes for a specific enzyme will not be able to produce that enzymes

Question 27

function 3: highly efficient

Answer 27

- a very small amount of enzymes bring about the change of a large amount of substrate - remain unchanged in the reaction they catalyse - the same enzyme molecule can be used over and over again eg: one molecule of enzyme catalase can catalyse the decomposition of about 600,000 molecules per second of hydrogen peroxide to water and oxygen at body temperature