Transcript Molecules of Life - CCRI Faculty Web

Molecules of Life
Chapter 3
Molecules
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Inorganic compound
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Nonliving matter
Salts, water
Organic compound
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Molecules of life
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Contains Carbon (C) and Hydrogen (H)
Carbon backbone
Carbon Chemistry
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Cell is mostly water
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The rest of the cell consists mostly of carbon-based molecules
Carbon is a versatile atom
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four electrons in an outer shell that holds eight
can share its electrons with other atoms to form up to four
covalent bonds
Organic Molecules
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Many molecules of life are macromolecules
(macromolecules contain many molecules joined together)
Monomers: Simple organic molecules that exist individually
Polymers: Large organic molecules form by combining
monomers
Polymer
Monomer
Carbohydrate
Monosaccharide
Protein
Amino acid
Lipids
Triglycerides
Nucleic acid
Nucleotide
Molecules of Life
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4 main classes of biological molecules
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1.
2.
3.
4.
Carbohydrates
Lipids
Proteins
Nucleic Acids
Carbohydrates
Carbohydrates
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Some Functions:
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Quick fuel
Short-term energy storage
Structure of organisms
Cell to cell recognition
Consist of C, H, and O atoms
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1:2:1 ratio
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“Saccharides”
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3 major classes:
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Monosaccharides
Disaccharides
Polysaccharides
Monosaccharides
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“simple sugars”; “one monomer of a sugar”
Dissolve easily in water
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hydrophilic
Glucose C6H12O6
Fructose
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Form of glucose
Disaccharides
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Short chain of two sugar
monomers
Two Monosaccharides
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Lactose, sucrose, maltose
Lactose = glucose + galactose
Polysaccharide
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“Complex” carbohydrate
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Glycogen
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Polysaccharide of glucose
Storage form of glucose in animals
Starch
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Composed of many glucose molecules
Storage form of glucose in plants
Cellulose
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Found in the cell walls of plants
Lipids
Lipids
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Cells use lipids to store energy
Hydrophobic
Functions:
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Energy Storage
Cushioning and Insulation
Found in the plasma membrane
3 main types:
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Fats & Oils
Phospholipids
Steroids
Fats
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Dietary fat consists largely of the
molecule triglyceride
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Combination of glycerol and three fatty
acids
Fats
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Unsaturated fatty acids
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Have less than the maximum number of hydrogens
bonded to the carbons
Saturated fatty acids
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Have the maximum number of hydrogens bonded to the
carbons
Most animal fats have a high proportion of saturated fatty
acids, which can be unhealthy
 Example: butter
Most plant oils tend to be low in saturated fatty acids
 Example: corn oil
Phospholipids
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Glycerol, two fatty
acids and a phosphate
group
Plasma membrane
Nonpolar tail
Polar heads
Proteins
Why Proteins??
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VERY important functions in cells
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Keratin and collagen have structural roles
Enzymes speed up chemical reactions of
metabolism
Responsible for transport of substances within
the body
Transport substances across cell membranes
Hormones that regulate cellular function
 Insulin
Proteins
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Made from amino acids
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20 various kinds
Amino acids linked to
one another by peptide
bonds
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Two amino acids bound
by a peptide bond is a
dipeptide
Three or more is a
polypeptide chain
Amino Acids
Peptide / Dipeptide
Polypeptide
Protein
Protein Structure
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Protein’s final shape
and chemical behavior
arise from it’s primary
structure
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Chain bends, folds, coils,
etc.
Denaturing
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When proteins lose their
shape
Nucleic Acids
Nucleotides and Nucleic Acids
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Nucleic acids
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Can be single stranded or double stranded
 DNA
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Deoxyribonucleic acid
genetic information
RNA
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Ribonucleic acid
used to build proteins
Nucleotides and Nucleic Acids
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Nucleic acids
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Built by nucleotides
 Phosphate
 Pentose sugar
 Nitrogen-containing base
DNA Composition
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DNA is built from four different
kinds of nucleotides
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One of four bases determines the
nucleotide:
 A - Adenine
 G - Guanine
 T - Thymine
 C – Cytosine
DNA consists of two strands of
nucleotides twisted into a double
helix
GAGA….a nucleotide repeat!!
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Base pairs
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Bases can only pair up with their corresponding “mate”
2 kinds:
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A–T
G–C
Amount of A = T
Amount of G = C
Can line up in any order
DNA Composition
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Nucleotides linked together by
covalent bonds
Bases of one strand linked to the
other by hydrogen bonds
The two strands run in opposite
directions
DNA into RNA
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RNA a big player!!
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Single strand
Sugar, phosphate group,
and a N-containing base
Bases are:
 A, C, G, and URACIL (U)