Chapter 4 Flashcards
Biological molecules
What are biological molecules?
These are molecules that contain the elements Carbon, Hydrogen, Oxygen, (Sulfur and Nitrogen for proteins)
What are monomers?
Monomers are repeating subunits of molecules.
What are macromolecules?
These are very large molecules constructed of repeating sub units (monomers).
What are Polymers?
Polymers are long chains of monomers held together by chemical bonds.
What are Carbohydrates?
These may be simple or complex sugars ex: Glucose.
They all contain Carbon, Hydrogen and Oxygen.
What are Monosaccharides?
These are sugars with a single carbon ring.
EX: Glucose & Fructose
What are Disaccharides?
These are sugars with 2 Carbon rings.
EX: Maltose & Sucrose
What are Polysaccarides?
These are sugars with more than 2 glucose molecules.
EX: Glycogen, Starch & Cellulose
What are Fats?
Fats are the solid form of a group of molecules called lipids.
When lipids are liquid, they’re called Oils.
A molecule of fat is made up of Carbon, Hydrogen and Oxygen.
What molecules are Fats made up of?
1 molecule of fat is made up of 3 molecules of organic acid called Fatty acids, and 1 molecule of Glycerol.
What are lipids and fats/oils used for?
- Lipids form part of the cell membrane and internal membranes like the NUCLEAR MEMBRANE.
- Droplets of fats/oils form a source of energy when stored in the cytoplasm.
What are Proteins?
-Proteins are long chains of amino acids held together by peptide bonds.
-They form cross-linkages that results in a particular shape.
-They all contain Carbon, Hydrogen, Oxygen, Nitrogen and Sulfur.
What are some examples of Proteins?
-There are structural proteins that contribute to the cell’s structure.
EX: Cell membranes, Ribosomes, Mitochondria.
-There are enzymes too, that control the rate of chemical reactions in the cell.
How many amino acids are there?
About 20 different types that are arranged in a particular sequence, making up thousands of combinations of proteins.
Give uses of water
-Water is a good solvent.
-It is used for many chemical reactions.
-It allows substances to move about.
What is Synthesis?
It is the build up of substances into new compounds.
Cells synthesize, breakdown, or change into one form or the other.
What is a Peptide bond?
It is the bond between amino acids to make Proteins.
What is a Glycosidic bond?
It is the bond between carbohydrates.
What does it mean when a protein denatures?
Denaturing means the cross linkages break down. The protein molecule loses its shape and can’t be used again.
Describe the structure of a DNA molecule
- Two strands are coiled together to form a double helix.
- These strands are made up of long chains of Nucleotides.
- Each strand has organic bases.
- Bonds between bases holds strands together.
- The bases always pair A-T and C-G.
What is a Nucelotide?
A Nucleotide is a 5 Carbon sugar molecule (Deoxyribose) joined to a Phosphate group (-PO3) and Organic base (A,T,C,G)
What are the Elements and Sub-units of Carbohydrates?
The elements present are Carbon, Hydrogen & Oxygen.
The Sub-units are Glucose.
What are the Elements and Sub-units of Fats/Oils?
The elements present are Carbon, Hydrogen & Oyxgen.
The sub-units are Fatty acids and glycerol.
What are the Elements and Sub-units of Proteins?
The elements are Carbon, Hydrogen, Oxygen, Nitrogen & Sulfur.
The sub-units are Amino acids (20 different forms).
What is the test for Starch?
Iodine solution.
If positive, colour changes yellow/brown to dark blue.
What is the test for Reducing sugar? (glucose)
Benedicts solution.
If positive, colour changes from Blue to brick red/orange.
What is the test for Proteins?
Biuret solution.
If positive, colour changes from Dark blue to Purple.
What is the test for Fats/Oils?
Ethanol emulsion.
If positive, the ethanol turns milky white and cloudy.
What is the test for Vitamin C?
DCPIP solution.
If positive, the colour changes from blue to colourless.
