2.8a Enzymes

2.8 understand the role of enzymes as biological catalysts in metabolic reactions

28a Enzymes

1. Catalyst = makes the reaction occur faster under moderate conditions. 
2. Metabolical reactions = biological reactions taking place in a cell, building molecules up or breaking them down. 
3. Lock and Key Hypothesis 
Enzymes have a particular shape Enzymes are proteins

a)  Enzyme
b) Active site - where the substrate (c) fits in. Called: COMPLEMENTARY 
(d) Activated Complex (substrate in active site)
(e) Products emerge from the enzyme (substrate has been broken down into two products) - (f)

The  Enzyme remains unchanged

Substrate -----> Product 

2.7 Lab Tests for glucose and starch

2.7 describe the tests for glucose and starch

1. Glucose (C6 H12 O6) positive test 
a) Take glucose powder and dissolve it in a test tube 
b) Add  Benedict's Reagent (blue) 
c) Take test tube and place in a water bath to boil (60-70C) for 2-3 minutes
d) Remove test tube
Result = colour change from blue to orange.














2. Starch positive test 
a) In solid form = white powder
b) Place some white powder into a spotting tile 
c) Add Iodine Solution (brown)
Result = colour change from brown to dark blue/black colour

2.6 Biological Molecules Structure

2.6 describe the structure of carbohydrates, proteins and lipids as large molecules made up from smaller basic units: starch and glycogen from simple sugar; protein from amino acids; lipid from fatty acids and glycerol

1. Carbohydrates (CHO) ---> Sugars (glucose) combine to form STARCH (plants) and GLYCOGEN (animals)

2. Proteins (CHON) ---> Amino Acids join together in long chains which join together to make proteins.
Broken down they form smaller molecules (the amino acids)


3. Lipids (CHO) ---> (have 2 different kind of molecules) --> Glycerol + Fatty acids which join together to form Lipids.

2.5 Elements in biological molecules

2.5 recall the chemical elements present in carbohydrates, proteins and lipids (fats and oils)

1. Carbohydrates --> Carbon, Hydrogen, and Oxygen ---> Sugars + Polysaccharides (starch)
2. Proteins           ---> Carbon, Hydrogen, Oxygen, and Nitrogen ---> Amino Acids + Proteins
3. Lipids              ----> Carbon, Hydrogen, and Oxygen ----> Fats (animals) and Oil (plants) 

2.4 Differences between Plant and Animal cell

2.4 describe the differences between plant and animal cells.

Animal Cell: 
Cell membrane
Nucleus
Cytoplasm 
Shape: Rounded
Store: Glycogen molecule (carbohydrate)

Plant Cell:
Cell MembraneNucleusCytoplasm
Cell wall
Chloroplasts
Shape: regular shape
Central Vacuole
Store: Starch molecule (carbohydrate)

Functions of parts of a call

2.3 describe the functions of the nucleus, cytoplasm, cell membrane, cell wall, chloroplast and vacuole

1. Plant Cell 
Vacuole = Stores molecules (amino acids, sugars etc)
Chloroplasts = Where photosynthesis occurs
Cell wall = Provides the protection and support for the cell. 

2. Animal cell

Cell Membrane = controls what goes and leaves the cell
Nucleus = Controls what the cell does
Cytoplasm = where chemical reactions take place eg: respiration.

2.2 Cell structure

Recognize cell structures, including the nucleus, cytoplasm, cell membrane, cell wall chloroplast and vacuole.  
N = nucleus
CM = Cell membrane
C= Cytoplasm
V= Vacuole
CW= Cell wall