Molecules, DNA and Kingdoms Flashcards
What are proteins made of?
Amino Acids
How many Amino Acids are there?
20 - Can be put in any order resulting in millions of different combinations
Why does the shape of a protein matter?
It helps carry out its job.
How to Test for Glucose?
Benedict’s solution - Add benedict’s solution to sample of food (solution), place in hot water bath (80 degrees Celsius) for 5 minutes;
If solution is red then high concentration of sugar. If Green, yellow or orange then still positive but less concentration than red.
How to test for Starch?
Iodine solution - Add a few drops of solution on a spotting tile. If starch is present then blue-black colour will show.
How to test for protein?
Biuret - Add 2cm cubed of water to sample and shake (If not already liquid). Add an equal volume of dilute potassium hydroxide and shake. Add 2 drops of 1% copper sulphate solution. If protein is present then pale purple colour will develop.
How to test for lipids?
Emulsion - Food sample placed on test tube. Add small volume of absolute ethanol and shake to dissolve and lipid in the alcohol. Add an equal volume of water. A cloudy white colour indicates the presence of lipids.
What is a chromosome?
A strand of DNA. Most cells contain pairs of chromosomes, both with the same genes.
What is a gene?
A short section of DNA within a chromosome. It codes for a specific protein which gives us characteristics.
What is a genome?
The total DNA for an organism - coding for all its characteristics.
What are the four bases?
Adenine pairs with Thymine
Cytosine pairs with Guanine
How is a nucleotide formed?
Nucleotide is formed of a sugar, a phosphate and nitrogenous base
What shape does The DNA take?
A Double Helix
What smaller units make carbohydrates?
Carbon, hydrogen and oxygen
What smaller units make lipids?
Carbon, hydrogen and oxygen
