proteiN proteiN – “N” stands for nitrogen. There is an “N” in the word proteiN The element Nitrogen is always present in proteiNs.

Parts of an amino acid The NH2 group is the amino group The COOH on right is called a carboxyl group. Carboxyl group is responsible for giving the amiNo acid it’s acid properties

Elements Present Used by organisms Related terms & info Carbon (C) Hydrogen (H) Oxygen (O) Nitrogen (N) (always those 4) Structure Enzymes Antibodies Hormones Pigments Peptide bond = the bond that holds amino acids together in protein molecules Dipeptide = two connected amino acids Polypeptide = 3 or more connected amino acids Building block of proteiNs: Amino Acid

Making Chains There are 20 essential amino acids that the human body needs. These 20 amino acids combine together to form long chains. These long chains of amino acids are known as proteins.

How are amino acid chains formed? By dehydration synthesis. Amino acids are linked by peptide bonds. Two amino acids liked together is known as a _________? Many amino acids linked together is known as a___________?

Peptide bonds are broken by hydrolysis Hydrolysis breaks the peptide bond by the addition of water (H 2 O)

What is occurring in this reaction Hydrolysis or Dehydration Synthesis?

Which one of these is an amino acid?

All amino acids are the same except for the R group

Proteins in the cell membrane Proteins are used in the cell membrane to aid in what kind of diffusion? They are used in what kind of transport?