the building blocks of life mrs. geist, biology swansboro high school, 2010-2011 1
TRANSCRIPT
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Warm-Up
What does the term “organic” mean to you?
Can you name foods rich in: carbohydrates/sugars lipids/fats, and proteins?
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Organic vs. Inorganic
Organic compounds: typically contain carbon (C) and are associated with life
Inorganic compounds: usually do not contain carbon and are associated with non-living things
Carbon is the building block of all living things!!
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Carbon
Has 4 electrons in its outermost shell 4 electrons to share Forms covalent bonds (shares electrons) Single, double, or triple bonds
Atoms of nitrogen (N), oxygen (O), and phosphorus (P) attach to carbon chains.
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Macromolecules—giant molecules
4 major classes: Carbohydrates Lipids Proteins Nucleic acids
Polymers- complex molecules Monomers- small molecules, single units
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Carbohydrates
Made of carbon (C), hydrogen (H), and oxygen (O)
Ex: sugars and starches
2 H: 1 O Major source of
energy
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Carbohydrates: Simple Sugars Simple
sugars (C6H12O6) smallest carbs. A.k.a.
monosaccharides
Ex: glucose, fructose, galactose
Cell’s main source of energy
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Carbohydrates: Disaccharides Disaccharide
(C12H22O11)- two monosaccharides together Ex: sucrose,
maltose, lactose
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Carbohydrates (cont’d.)
Polysaccharides- many monosaccharides
4 major classes of polysaccharides:1. Starch- plant storage of glucose2. Glycogen- animal storage of glucose3. Cellulose- plants use for structural support
Most abundant organic molecule on Earth Indigestible bulk (or “fiber”)
4. Chitin- animals use for support, insect skeletons
2nd most abundant organic molecule on Earth
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Warm-Up 8/31
In your own words, what is an organic macromolecule?
What do the terms saturated and unsaturated fat mean to you?
Where might we find protein in the body?
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Lipids
Made up of carbon (C), hydrogen (H), and oxygen (O)
Functions: Store energy Provide insulation Important parts of cell membranes
(phospholipids) Waterproof coverings (waxes, ex: bird
feathers) Not soluble in water
Ex: fats, oils, waxes, steroids, phospholipids
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Lipids (cont’d.)
Structure: 3 fatty acids
Long chains of C with H attached
1 glycerol Alcohol with a hydroxyl
(-OH) group on each of its 3 C atoms
Dehydration synthesis: attaches these parts
Removal of water (H2O)
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Lipids: Saturated vs. Unsaturated
Saturated Unsaturated
Solid at room temperature
Liquid at room temperature
Contains lots of H Contains less H
Single bonds between C atoms
1+ double bonds between C atoms
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Proteins
Made up of nitrogen (N), carbon (C), hydrogen (H), and oxygen (O)
Monomer: amino acids Structure:
Amino group (-NH2) on 1 end Carboxyl group (-COOH) on the other end Side chain (or R group) that differs for
each of the 20 amino acids
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Proteins: 4 levels of organization1. Primary: sequence of amino acids2. Secondary: the amino acids within a
chain can be twisted or folded Ex: alpha helices, beta pleated sheets
3. Tertiary: the chain itself is folded4. Quaternary: If the protein has >1
chain, each chain has a specific arrangement in space
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Protein Functions
Some proteins control the rate of reactions and regulate cell processes (called enzymes). Act as catalysts- speed up chemical
reactions some form bones, muscles, skin, and
ligaments. Others transport substances into/out of
cells Help to fight disease.
Enyzmes as catalysts
Enzymes are proteins that act as biological catalysts. Catalyst- speeds up
the rate of a chemical reaction.
Speed up reactions that are too slow or have activation energies that are too high to make them practical for living tissue.
Enzymes act by lowering the activation energy.
Functions of Enzymes
Regulating chemical pathways.
Making material that cells need.
Releasing energy. Transferring
information.
Enyzmes as catalysts
For a chemical reaction to take place, the reactants must collide with enough energy to break existing bonds and form new bonds
If reactants do not have enough energy, no reaction will take place.
Enzymes
Enzymes are very specific, generally catalyzing only one chemical reaction.
For this reason, part of an enzyme’s name is usually derived from the reaction it catalyzes. Add –ase ending. I.e. lipase I.e. proteinase
The Enzyme-Substrate Complex Enzymes provide a site where reactants can be brought
together to react, reducing the energy needed for reaction. The reactants are known as substrates. The enzyme and substrates remain bound together until the
reaction is done and the substrates are converted to products. The products of the reaction are released and the enzyme is
free to start the process again.
Copyright Pearson Prentice Hall
The cell theory states that new cells are produced from nonliving material. existing cells. cytoplasm. animals.
Copyright Pearson Prentice Hall
The person who first used the term cell wasa. Matthias Schleiden.b. Lynn Margulis.c. Anton van Leeuwenhoek.d. Robert Hooke.
An Enzyme-Catalyzed Reaction
Substrates: glucose and ATP
Enzyme: hexokinase Substrates bind to
enzyme, forming an enzyme-substrate complex.
The fit is so precise that the active site and substrates are often compared to a lock and key.
Regulation of Enzyme Activity
Enzymes work best at certain pH and temperature ranges and can be affected by such changes.
Many enzymes are affected by changes in temperature.
Cells can regulate the activities of enzymes.
Most cells contain proteins that help to turn key enzymes “on” and “off” at critical stages in the life of the cell.
Nucleic Acids
Function: store and transmit hereditary, or genetic, information.
2 kinds of nucleic acids: 1. ribonucleic acid
(RNA)2. deoxyribonucleic
acid (DNA).
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Nucleic Acids
Monomer = nucleotides, which are composed of 3 parts: 5-carbon sugar- deoxyribose (DNA) or ribose
(RNA) Nitrogen base- adenine (A), thymine (T),
cytosine (C), guanine (G), uracil (U) Phosphate group- contains phosphorus (P) and
oxygen (O) 2 Types:
Deoxyribonucleic Acid (DNA) Ribonucleic Acid (RNA):
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Ribonucleic Acid (RNA)
single helix Plays a role in
manufacture of proteins
Enzyme (speed up reactions)
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Nucleotides
DNA and RNA Adenine (A) Guanine (G) Cytosine (C)
DNA only Thymine (T)
RNA only Uracil (U)
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3 parts of a nucleotide
5-carbon sugar (deoxyribose in DNA or ribose in RNA)
Nucleotide base Phosphate group
The DNA and RNA Strand
Nucleotide + Nucleotide(n)
= DNA (or RNA) strand
2005 VisiScience Corporation. All Rights Reserved.
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Does temperature affect an enzyme reaction? (pp. 164-165)
Problem: Does the enzyme peroxidase work in cold temperatures? Does peroxidase work better at higher
temperatures? After being frozen or boiled?
Hypothesis: “If…, then …” statement. Materials: clock, beakers, kitchen knife,
tongs, potato, ice, hot plates, thermometers, 3% hydrogen peroxide (H2O2), hot gloves
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Peroxidase
2H2O2 2H2O + O2
Hydrogen Peroxide water + oxygen gas
Hydrogen peroxide is damaging to cells
Peroxidase speeds up the breakdown of hydrogen peroxide
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Planning Experiment
Hypothesis Boiling, ice bath,
warm water bath, room temperature
Steps to be taken Add 1 drop H2O2
to the potato slice and observe what happens
What data will you collect? How will you record them?
What factors should be controlled?
How will you achieve those temperatures?
Carry out the expt.