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1

What are proteins?

Proteins – the most abundant of all biomolecules
Other biomolecules – nucleic acid, carbohydrates, lipids–
Proteins are required for building and repair of body tissues
Involved in structural support & bodily movement
Can also be a source of energy
Immunoglobulins –
Antibodies that defend the body against infectious agents
Transport proteins – hemoglobin and myoglobin

The structure of a protein determines its function

2

What are proteins made of?

Proteins (polypeptides) are organic compounds made of amino acids
Amino acids – basic building blocks of all proteins
The end products of protein digestion are amino acids
Amino acids are joined together by peptide bonds between the carboxyl and amino groups (amine)
Growth, repair and maintenance of all cells depends on amino acids

3

How many amino acids?

There are 20 different natural amino acids
Each with a different R group (side chain structure determines the identity)
10 of the 20 amino acids cannot be produced in the body
Must be supplied through the diet in the form of protein – known as essential amino acids
Primary purpose of amino acids:
The synthesis of body proteins, including plasma, intracellular and structural protein

4

What elements are in proteins?

Proteins contain the same elements as carbohydrates and fat, with the addition of nitrogen
Carbon, hydrogen, oxygen and nitrogen

5

what are primary protein structures?

The sequence (linear) in which amino acids are lined up and connected by peptide bonds
Dipeptide – Two amino acids combine
Polypeptide – Many (> 3) amino acids combine
The long repetitive sequence of amino acids that make a continuous chain is called the protein’s backbone

6

what are secondary protein structures?

Twisting or folding of the protein chain (primary) into a spiral or coil
Called α helix; or parallel strands – called β pleated sheet
Held by hydrogen bonds between the H of the NH of one amino acid and the O of the C=O of another amino acid

7

what are tertiary protein structures?

Protein chains folded into specific three-dimensional shape held by:
Hydrogen bonds
Ionic bonds
Disulfide bonds (-S-S- bonds)
This shape is vital for the function of enzymes and the biological activity of other proteins

interplay of sidechains

8

what are 4arny protein structures?

Combination of several protein units (subunits) with its own complete structure
Example – Hemoglobin
noncovalent interactions

9

How are chemical structures catalyzed?

All biochemical reactions are catalyzed by enzymes which are proteins

10

What are cell structure and extracellular matrices composed of?

Structure of cells and extracellular matrix are made from collagen…most abundant protein in the body

11

What are nucleotides?

The building blocks of DNA and RNA
Determine the genetic structure of life
Units that make up nucleic acids like RNA and DNA
Function to transport and transform cellular energy and regulate enzymes
Most nucleotides are adenine (A), guanine (G) - purine, thymine (T), cytosine (C), pyrimidine and urasil (U) They are joined by hydrogen bonds

12

What is a gene?

A segment of DNA that contains the information required for the synthesis of a functional biological product is referred to as a GENE

13

Describe DNA/RNA structure

Structure consist of – A pentose sugar like ribose or deoxyribose, a phosphate or polyphosphate group and a nitrogen containing base
Represented by: N – S – P
Example – Adenosine monophosphate (AMP)
Has low-energy
ATP – High energy usable by all body cells
2 phosphoric acid groups added to AMP

14

What is DNA?

DNA - Deoxyribonucleic acid
Long-term information storage (a chemical information storage medium)
A nucleic acid that contain genetic instructions
Most DNA is located in the cell nucleus (called nuclear DNA)
Nearly every cell in a person’s body has the same DNA

15

What does the spine of DNA look like?

Has a spine ( backbone) of alternating (repeating) deoxyribose (sugar) and phosphate molecule covalently bonded in a long chain
The 2 chains are held together by hydrogen bonds between the bases
Each sugar group is attached to a nucleotide / nitrogenous base (responsible for genetic coding

16

Describe the layers of DNA structure

DNA polynucleotide chains pair up with one another (primary structure)
Bond together in twisted double strand (double helix)
Double-helix wraps around some proteins (tertiary structure)

17

Describe DNA replication

DNA replication or DNA synthesis, is the process of copying a double-stranded DNA strand
The strands separate at the nucleotide base
Each chain becomes a template for the new chain (double helix)
Each chain attract additional nucleotide

18

Describe RNA

A chain of nucleotides produced by transcription of DNA
Single chain or strand
The sugar is ribose and the base thymine is replaced by uracil
RNA is made up of – nucleotides (with a nitrogenous base), a ribose sugar, and a phosphate group
RNA – transfer information from DNA to the ribosome

19

How does transcription work?

When a particular protein is needed by a cell –
DNA chain separates
One chain act as a template for RNA
DNA sequence is enzymatically copied by an RNA polymerase to produce a complementary RNA (mRNA)
In other words, the transfer of genetic information from DNA into RNA

20

What is a codon?

Codon – Grouping of three nucleotides on a mRNA molecule
Codes for one of the 20 natural amino acids

21

What is mRNA?

mRNA / messenger RNA
Contain/carry the information on the primary sequence of amino acids in a protein to be synthesized (in the cytoplasm)

22

What is tRNA

tRNA / Transfer RNA
"reads" the mRNA codon by using its own anticodon
carries the amino acid to be incorporated into the developing protein
each tRNA is specific for a certain amino acid

23

What is rRNA

rRNA / Ribosomal RNA
rRNA and protein combine to form a nucleoprotein called a ribosome
Ribosome serves as the site and carries the enzyme necessary for protein synthesis

24

What is a mutation?

A change in copying DNA
Changes in a genomic sequence
Could be inherited or acquired
Changes could be harmful or have no effect
The bases of Sickle Cell Disease – Change of one amino acid in the hemoglobin structure

25

What is Fragile X?

Fragile X – DNA test (genetic material)
Fragile X is the most common inherited cause of mental impairment and the most common known cause of autism

26

What is Downs Syndrome

Downs Syndrome – Chromosome 21 abnormality

27

What is cystic fibrosis

Affects the entire body, causing progressive disability and often early death (lungs, muscle)

28

What is a solution

A solution is a homogeneous and transparent mixture involving – solute(s) and solvent
Solute – the dissolved substance
Present in lesser amount
Solvent – the substance in which the solute is dissolved
A solution can pass through a filter

29

What is an ionic solute?

An ionic solute dissolves in water (polar solvent) because the polar water molecules attract and pulls the ions into solution where they become hydrated
Example NaCl crystals undergo
hydration as water molecules surround each ion and pulls it into solution

30

What are electrolytes?

Electrolytes … important in maintaining the proper functioning of cells and organs
Electrolytes… Sodium , Potassium, Chloride and Bicarbonate can be measured in blood

Solution that carries (conducts) electricity
Acids, bases, and salts form electrolytes because they produce ions when dissolved in H2O
Ions act as moving electrical charges and carry electricity