Polymers long chains of AMINO ACIDS

1
PROTEINS

• Polymers (long chains) of AMINO ACIDS
• arranged in specific sequence
• linked by PEPTIDE BONDS
• range in length from a
• few to 1000

2
AMINO ACIDS

• building blocks of proteins
• there are 20 common amino acids
• structure of an amino acid
• elements included in a
• protein
• -carbon
• -hydrogen
• -oxygen
• -nitrogen
• -sulfur (usually)

3

• Amino acids are linked together through
  DEHYDRATION SYNTHESIS to form PEPTIDE BONDS

4
PROTEIN STRUCTURE

• a proteins function depends on its specific 3-D
  shape

5
(No Transcript)
6
(No Transcript)
7
Protein Shape

• determined by environmental
• conditions
• DENATURATION protein loses its natural shape,
  and therefore loses its function! This can be
  caused by
• extreme heat
• pH changes

8
HEAT
9
Functions of Proteins

• structural support (e.g. hair, nails)
• signaling (e.g. hormones)

10
Functions of Proteins

• movement (contraction
• of muscles)
• transporting oxygen in the
• blood

11
Functions of Proteins

• defense (antibodies of immune system)
• catalysis of reactions (ENZYMES)

12
PROTEINS WORKING AS ENZYMES

• ENZYMES
• are proteins
• control the speed of reactions (often they
  increase the speed of reactions)

13

• are not changed or used up by a reaction can
  be used over and over

14

• each enzyme is specific to a SUBSTRATE
• SUBSTRATE the substance the enzyme acts on
•  
• Substrate gt enzyme-sub.gt product
• complex
• enzyme enzyme

15
(No Transcript)
16

• ACTIVE SITE region of an enzyme which binds to
  the substrate
• is usually a pocket or groove on surface
• compatible fit between shape of enzymes active
  site and shape of substrate

17
(No Transcript)
18
(No Transcript)
19
Factors Affecting Enzyme Activity

• Temperature
• as temp increases, reaction rate increases
• BUT, if temp gets too high, enzyme denatures and
  loses its shape and function
• optimal range for human enzymes 35-40C

20
(No Transcript)
21

• pH
• -optimal range for most enzymes pH 6-8
• some enzymes operate best at extremes of pH
  (e.g. digestive enzyme pepsin, found in the
  acidic environment of the stomach, works best at
  pH 2)

22
Nucleic Acids

• nucleic acids store and transmit hereditary
  information
• Two types of nucleic acids
• DNA
• RNA

23
Structure of Nucleic Acids

• polymers made up of monomers called NUCLEOTIDES
• Elements present
• -carbon
• -hydrogen
• -oxygen
• -nitrogen
• -phosphorus

24

• each nucleotide consists
• of
• 1. a simple sugar
• -deoxyribose in DNA
• -ribose in RNA
•  
• 2.   phosphate group
•  
• 3.   a base (e.g. in DNA, the bases are A, G, C,
  and T)

25

• nucleotides are joined together in DEHYDRATION
  SYNTHESIS
• results in a backbone with a repeating pattern
  of sugar-phosphate-sugar-phosphate...

26
1. DNA Deoxyribonucleic acid

• forms the genetic code - the instructions for the
  proteins (amino acid sequences) of an organisms
  proteins
• is copied and passed
• from one generation
• of cells to another

27
2. RNA Ribonucleic acid

• functions in the actual
• synthesis of proteins
• coded for by DNA