Proteins Flashcards
Elements in lipids?
CHO
Elements in proteins?
CHON
Elements in carbohydrates?
CHO
Functions of proteins?
Enzymes
Growth and repair of cells
Structural components (muscles, bones etc)
Membrane carriers and pores (cells)
Many hormones are proteins
How many different amino acids are there?
20
What can the R group be?
Polar and uncharged
Polar and negatively charged (acidic)
Polar and positively charged (basic)
Non-polar and hydrophobic
Nitrogen can only bond with….
3
Oxygen can only bond with…
2
Carbon can only bond with…
4
Hydrogen can only bond with….
1
What is the test for proteins?
Place the sample into a test tube with an equal volume of sodium hydroxide solution
Add a few drops of copper (II) sulphate solution and mix gently
Purple -> peptide bonds are present- therefore proteins are present
No colour change (blue)- no protein present
What are proteins linked by?
Peptide bonds
How many amino acids are there in the human body?
26
How man amino acids form proteins?
20
Are amino acids soluble or insoluble?
Soluble
What is the amino group?
NH2
What is the carboxyl group?
COOH
What are the different side chains called?
R groups
What makes the amino acids different to each other?
The R groups
Are R groups hydrophilic or hydrophobic?
Hydrophilic
What are the hydrophobic R groups referred to as?
Non-polar
What are the 4 categories of R group?
Polar and uncharged
Polar and negatively charged (acidic)
Non-polar and positively charged (basic)
Non-polar and hydrophobic
How are proteins formed?
Polymers formed by the condensation reaction of amino acids via peptide links
What reaction is formed when a protein is formed?
A condensation reaction
What is lost in a condensation reaction?
A molecule of water
What bond is formed during a condensation reaction?
A peptide link/bond
What are proteins hydrolysed into?
Free amino acids by hydrolytic enzymes
