Biological Molecules

1
Biological Molecules

• Biology
• Mr. Evans

2
Objectives

• Define a sugar and describe how polysaccharides
  are formed
• Describe solubility and energy storage properties
  of lipids
• Explore factors that affect the 3D structure of
  proteins
• Define nucleic acids and describe their functions

3
Organic Compounds

• Atoms form molecules
• Molecules combine to form Macromolecules
• Main component of macromolecules is carbon
• 4 Types of Macromolecules found in all living
  things
• Carbohydrates
• Lipids
• Proteins
• Nucleic acids
• Organic Compounds- molecules with C-C bonds
• Carbon can form a total of four bonds
  combination of single, double, or triple bonds
• Can form long chains or rings

4
Terminology

• Monomers smaller, simple molecule that can join
  together to form larger molecule
• Mono single mer part
• Polymers complex molecule formed when 2 or more
  monomers combine
• poly many
• polymerization when polymer formed
• condensation reaction takes place (releases 2 H
  and 1 O)

5
Carbohydrates

• Carbohydrate- made of C, H, and O
• Ratio of elements C1H2O1
• Ribose is C5H10O5
• Stores energy in C-H bonds

Ribose
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Types of Carbohydrates

• Monosaccharide (monomer)- few carbons linked
  together
• Simple sugars
• e.g. Glucose (C6H12O6)
• Polysaccharides (polymer)- long chains of
  monosaccharides
• Complex carbohydrates
• Insoluble in H2O
• Stored in special reserves in cell
• e.g. starch (foods we eat) and cellulose (plant
  structure)

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Starch
Glucose
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8
Lipids

• Lipid- not soluble in water, but is soluble in
  oil
• Made of C, H, O
• C-H bonds good for storing energy
• Structure is 3 long chains of C-H units
• Lipid structure is a glycerol molecule attached
  to three chains of fatty acids made of C-H units

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Lipid Structure
Triglyceride Molecule
Glycerol

3 fatty acid chains
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Types of Lipids

• Saturated Fats
• Butter, cheese, chocolate, beef
• Unsaturated Fats
• Avocado, olives, peanuts, fish
• Steroids
• Sex hormones, cholesterol, chlorophyll
• Wax
• Earwax, beeswax

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Saturated Fats

• Carbons are saturated with hydrogen
• 3 fatty acid chains line up side by side
• Animal fats
• Solids at room temperature
• See Table 2.1

12
Unsaturated Fats

• Carbons are not saturated with hydrogen
• Carbon chain contains double bonds
• 3 fatty acid chains have kinks
• Liquid at room temperature vegetable oils
• See Table 2.1

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Saturated and Unsaturated Fats

• Saturated fat
• Unsaturated Fat

14
Proteins

• Proteins- composed of long chains of amino acids
• 20 different types of amino acids (AA)
• Made of C, H, O, and N
• AAs join at peptide bonds

15
Protein Structure

• Primary Structure (1)
• String of AAs
• Actual sequence of AA in protein
• Most basic structure
• Usually only a few 100 AAs long

16
Protein Structure

• Secondary Structure (2)- initial coiling or
  bending of AA chain due to molecular interactions
• alpha helix (keratin protein in hair)
• Beta pleated sheets (silk strands)

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Protein Structure
beta pleated sheet
alpha helix
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Protein Structure

• Tertiary Structure (3)- folding chain into
  compact mass

19
Protein Structure

• Quaternary Structure (4)- 2 or more folded
  proteins combined
• e.g. Hemoglobin

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Protein Function and Activity

• Provide Structure
• Collagen makes up cartilage and tendons
• Enzymes
• Increase rate of chemical reactions
• Denature- protein structure breaks down
• Caused by
• Heat
• pH extremes
• Chemicals that disrupt H bonding

21
DNA RNA

• Made of nucleotides
• Nucleotides are grouped into units called genes
• Made of C, H, O, N, and a base

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DNA (Double Helix)

• DNA- encodes sequences for cellular proteins
• Tells where proteins are made
• DNA is wound up into chromosomes
• DNA bases
• Adenine
• Thymine
• Cytosine
• Guanine

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RNA (Protein Synthesis)

• mRNA- carries DNA message
• rRNA- makes ribosomes to process mRNA
• tRNA- forms proteins from RNA message
• RNA bases
• Adenine
• Uracil (not Thymine)
• Guanine
• Cytosine

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Thought Questions

• What element makes up the backbone of all organic
  molecules?
• Carbon
• What is the ratio of elements in carbohydrates?
• C1H2O1
• What is the formula for glucose?
• C6H12O6
• The scientific name for complex carbos.
• Polysaccharides

25
Thought Questions

• What are the two energy storing biomolecules?
• Carbos Lipids
• Whats the difference between sat. unsat. fats?
• Sat. fats have no double bonds
• Vegetable fats are what type of fat?
• Unsat. fats

26
Thought Questions

• The actual AA sequence of a protein is called
• Primary Structure
• What is Quaternary structure?
• 2 or more folded proteins combined.
• Give 2 major functions of proteins.
• Structure and enzymes
• What factors can denature (break down) proteins?
• Heat, pH, disrupting H-bonding

27
Thought Questions

• What is DNAs job?
• To encode info for making proteins
• How many bases does DNA have?
• 4
• What are they?
• A, C, T, G
• What is the difference between RNA and DNA?
• Uracil replaces Thymine 3 types of RNA

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The Organic Compounds That are Vital to Life
C
N
O
H
Organic Compounds Elements Monomers (smallest parts) Function
Carbohydrates C, H, O Monosaccharide Energy
Protein C, H, O, N Amino Acids Building Blocks Reactions/ Enzymes
Lipids C, H, O Glycerol Fatty Acids Stored Energy Membranes Messengers
Nucleic Acids (DNA, RNA) C, H, O, N, P Nucleotides Genetic Code