macromolecules - biowilson.weebly.com · macromolecules • large organic molecules. • also...
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Macromolecules
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Organic Compounds • Compounds that contain CARBON
are called organic.
• 4 Elements found in organisms – Carbon -Oxygen
– Hydrogen -Nitrogen
• Macromolecules are large organic molecules.
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Carbon (C) • Carbon has 4 electrons in outer shell.
• Carbon can form covalent bonds with as many as 4 other atoms (elements).
• Usually with C, H, O or N. (CHON)
• Example: CH4(methane)
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Macromolecules
• Large organic molecules. • Also called POLYMERS. • Made up of smaller “building blocks” called MONOMERS.
• Examples: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids (DNA and RNA)
Polygons
Polygamy Polyester
What is so special about Macromolecules?
• Most of the energy
used by an organism
comes from
GLUCOSE
– By breaking the
chemical bonds and
releasing the energy
via cellular respiration
• Other “macros”
provide vital
functions such as
proteins (enzymes)
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Carbohydrates
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Carbohydrates = Sugars
• Provides energy and support – Support: Cellulose for plants – Energy: breakdown of glucose (cellular respiration)
• Range from small molecules to large molecules.
CARBOHYDRATES
Each carbohydrate is made up of…
THINK: “CHO”
Types of Carbohydrates
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A. monosaccharide B. disaccharide C. polysaccharide
Glucose • Most common monomer or
monosaccharide
• 1 glucose molecule
– C6H
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6 or 1:2:1 ratio
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Carbohydrates- Simple
Monosaccharide: one sugar unit
Examples: glucose
deoxyribose
ribose
fructose
galactose
glucose
Examples of Monosaccharides
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• Glucose – sugar (beet, cane)
• Fructose – fruits
• Galactose – dairy
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Carbohydrates- Simple
Disaccharide: two sugar unit
Examples: – Sucrose (glucose+fructose)
– Lactose (glucose+galactose)
– Maltose (glucose+glucose)
glucose glucose
Examples of Disaccharides
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• Sucrose – table sugar
• Lactose – dairy
• Maltose - sweetener
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Carbohydrates - Complex Polysaccharide: many sugar units
Examples: starch (bread, potatoes)
glycogen (beef muscle)
cellulose (lettuce, corn)
glucose glucose
glucose glucose
glucose glucose
glucose glucose
cellulose
Examples of Polysaccharides
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• Starch – sugar (beet, cane)
• Cellulose – fruit and vegetables
• Chitin – exoskeleton
• Glycogen - meat
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Lipids
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Lipids • General term for organic molecules which are not soluble in water.
• Lipids are soluble in hydrophobic solvents.
• Remember: “stores the most energy” • Examples: 1. Fats 2. Phospholipids 3. Oils 4. Waxes 5. Steroid hormones 6. Triglycerides
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Lipids Six functions of lipids: 1. Long term energy storage 2. Protection against heat loss (insulation) 3. Protection against physical shock 4. Protection against water loss 5. Chemical messengers (hormones) 6. Major component of cell membranes (phospholipids)
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Lipids Triglycerides: -composed of 1 glycerol and 3 fatty acids.
H
H-C----O
H-C----O
H-C----O
H
glycerol
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
fatty acids (chains)
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
O
C-CH2-CH2-CH2-CH
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Fatty Acids There are two kinds of fatty acids- you may see
these on food labels:
1. Saturated fatty acids: no double bonds (bad)
2. Unsaturated fatty acids: double bonds (good)
O
C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3 saturated
O
C-CH2-CH2-CH2-CH unsaturated
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Proteins
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Proteins (Polypeptides) • Made up of amino acids (20 different kinds)
bonded together by peptide bonds (polypeptides).
• Six functions of proteins: 1. Storage: albumin (egg white) 2. Transport: hemoglobin transport 02
3. Regulatory: hormones 4. Movement: muscles 5. Structural: membranes, hair, nails 6. Enzymes: cellular reactions
MORE ON PROTEINS…
The following slides give you a little more in depth info on things that are made of
proteins…
Muscles, ligaments, tendons, and bones
Without these particular structural proteins, we would look more like this….
Hair and Nails
Microscope View of Skin and Nails
This is skin This is a nail
Cell Membrane
The cell membrane surrounds everything in a cell so it
doesn’t leak out. It is kind of like the balloon in
a water balloon.
The cell membrane is made mostly of protein AND lipids or phospholipid bilayer.
Enzymes • Main function is to act as a catalyst to speed up
chemical reactions. – KEY: Enzymes only speed up the process….they DO
NOT change the process
• Names of enzymes generally end in –ase. – Example: lactase, amylase, protease, maltase, etc.
• Helps an organism maintain homeostasis.
• Enzymes are everywhere……all biological processes involve enzymes.
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How does an enzyme work?
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• The enzyme weakens the chemical bonds of the substrate (e.g. lactose) which decreases the amount of energy needed to active the chemical reaction for the breakdown
• The enzyme enables the
breakage of the chemical bond to happen more efficiently!
Why is this important?
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Helps organisms conserve energy….more efficient!
How does an enzyme work? continued • Enzymes only work on a specific substrate (or
substance)
• Substrate is the substance that is being “processed” (i.e. broken down) or changed
• Active site is where chemical reaction between the enzyme and substrate occurs – Point of contact
– “Lock and key” mechanism
– Right key (size & shape)
to fit lock
• Enzyme problems: – Lactose intolerance 33
Lock and Key
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The right shape
and size must fit to active reaction!
Induced Fit
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• With some enzymes, the lock and key analogy doesn’t fit
• Induced fit: • The substrate changes (or induces) the shape
of the active site to make the active site conform and fit the shape of the substrate.
• Occurs when the substrate attaches to the right enzyme
• During this process, the bonds in the substrate weaken and thus reducing activation energy
Induced Fit Model
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Factors Affecting Enzymes
The following alter the rate of reaction:
Environmental Conditions
Cofactors & coenzymes
Enzyme inhibitors
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Factors Affecting Enzymes • Environmental Conditions
– Temperature • Increased temperature can denature the enzyme
• Denature= the deactivation or breakdown of the enzyme – Enzymes can “unfold” due to denaturing which cause permanent
damage to the enzyme and decreased rate of reaction
• Optimal temperatures for enzymes are different for different enzymes and organisms…humans it is 37°C
– pH and acidity
– Ion Concentrations • Too salty; too many enzymes; too many substrates
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Factors Affecting Enzymes • Cofactors and coenzymes
– Enzymes that require another enzyme to carry out reaction
– Examples: vitamins, iron, and zinc
• Enzyme inhibitors – Chemicals that reduce or inhibit enzyme reactions
– Examples: drugs or other chemicals that act as substrates and plug up the enzyme
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Nucleic Acids
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Nucleic acids
• Two types: a. Deoxyribonucleic acid (DNA- double helix)
b. Ribonucleic acid (RNA-single strand)
• Nucleic acids are composed of long chains of nucleotides
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Nucleic acids • Nucleotides include: phosphate group pentose sugar (5-carbon) nitrogenous bases: adenine (A) thymine (T) DNA only uracil (U) RNA only cytosine (C) guanine (G)
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Nucleotide
O
O=P-O
O
Phosphate
Group
N Nitrogenous base
(A, G, C, or T)
CH2
O
C1 C4
C3 C2
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Sugar
(deoxyribose)
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DNA - double helix
P
P
P
O
O
O
1
2 3
4
5
5
3
3
5
P
P
P O
O
O
1
2 3
4
5
5
3
5
3
G C
T A