Chapter 2
Chemistry of Life
Biology II
Living things consist of atoms of different elements.
•An ________ is the smallest basic unit of __________.
•An ___________ is one type of ____________.
•An atom has a _____________ and _______________.
–The nucleus has ____________ and ____________.
–Electrons are in _____________________________________.
Draw the atom identifying the protons, neutrons, & electrons.
•Atoms have energy levels…
–__________________ the nucleus in which _______________(___)
are located
•The outer most energy level…
–Determines how _________________ or covalent __________
•A compound is made of atoms of __________________________ together.
–____________ (_______)
–___________________ (______)
–many other ______________________ compounds in living things
“How are elements different from compounds?”
Answer:
Ions form when atoms gain or lose electrons.
•An ion is an atom that has _____________________ one or more _______.
–___________ ions
–___________ ions
•___________ bonds form between _____________________ ions.
•Positive ion:
–Form when atoms ___________ e–Atoms that have _____________ e–Ex.
•Negative ions:
–Atoms __________ e–If they have nearly a _____________________
–Ex.
Atoms share pairs of electrons in covalent bonds.
•A ____________ bond forms when atoms __________________ of
electrons.
–_____________ covalent bonds
–_____________ molecules
Ex.
“What happens to electron in outer energy levels when two atoms form a
covalent bond?”
Answer:
Life depends on hydrogen bonds in water.
•Water is a _______________.
–Polar molecules have _________________ regions.
–Due to ___________ pull of e–________________ molecules do not have charged regions.
– ________________ bonds form between slightly positive hydrogen
atoms and slightly negative atoms.
•Hydrogen bonds are responsible for ______ important properties of water.
–____________________
–must __________________ to change temperature.
–____________________ temperature
–________________
–Causes ________________ & water ___________
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–________________
–Helps _________________
“How are hydrogen bonds silmilar to ionic bonds?”
Answer:
Many compounds dissolve in water.
•A ___________ is formed when one substance dissolves in another.
–A solution is a _________________ mixture.
–___________________________ substances.
–________________________ a solvent.
•“_______________________”
–Polar solvents dissolve __________________.
–Nonpolar solvents dissolve __________________.
–Polar substances and nonpolar substances generally ___________
_____________.
“What are solvent & solutes in beverages that you drink?”
Answer:
Some compounds form acids or bases.
•An acid releases a ________________ when it dissolves in water.
–______________ concentration
–pH __________________
•A base __________________________ from a solution.
–___________________ concentration
–pH ___________________
•A __________________ solution has a pH of 7.
•Most organisms need to keep their pH in a ______________.
–Human blood pH=______
–Bile pH=______
–Stomach acid ______
–Azalea plants need soil at _____
–Large changes are ___________
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“Cells have higher H+ concentration than blood. Which has a higher pH?”
Answer:
Carbon is special because they have unique bonding properties.
•Carbon forms covalent bonds with up to four _____________, including
other ___________ atoms.
•Carbon-based molecules have __________ general types of structures.
–__________ chain
–__________chain
–_________
•Many carbon-based molecules are made of many ________________
bonded together.
–_____________ are the individual subunits.
–Smaller molecule that is a _____________ in a larger.
–______________ are made of many monomers.
–(___________________)
“Write your own analogy for the formation of a polymer from monomers.”
Answer:
Four main types of carbon-based molecules are found in living things.
•Carbohydrates are made of ________________________________
–Carbohydrates include __________ and ___________.
–Monosaccharides are ________________.
–Ex.
–Polysaccharides include ______________, ___________, and
glycogen.
–Ex.
•_______________ is an example of a monomer (__________________)
•Starch is polymer (__________________)
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“Draw a simple monosaccharide & polysaccharide, then label starch or
glucose.”
Functions:
•Carbohydrates can be __________________________________ for cells.
•Some carbohydrates are part of ____________________.
•Lipids are nonpolar molecules that include _______, _________, and
cholesterol.
–Many contain __________ chains called _____________.
–Fats and oils contain fatty acids bonded to ____________.
•Lipids have several different ________________.
–___________________ as a source of ___________
–make up _________________
–used to make _______________
•Fats and oils have different types of fatty acids.
–_______________ fatty acids
–_______________ fatty acids
•____________________ make up all cell membranes.
–___________ phosphate “________”
–___________ fatty acid “_______”
“What 4 things make up a phospholipid?”
Answer:
“What is a phospholipid used for?”
Answer:
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“What 4 things make up a triglyceride?”
Answer:
“What is a triglyceride used for?”
Answer:
•Proteins are _______________________ monomers.
–Twenty different amino acids are used to _________________ in
organisms.
–Amino acids differ in ______________, or _____________.
–Amino acids are linked by ___________________.
•Proteins differ in the ______________ and ___________ of amino acids.
–Amino acids interact to give a protein its __________.
–Your body only makes ____________
–Incorrect amino acids change a protein’s ___________and
__________.
–Protein = _______________
Functions:
•There are MANY
–Can be ______________
–Used for __________________________
–_______________ movement
–Function is determined by __________________
•Example…
•__________________ are polymers of monomers called _____________.
–Nucleotides are made of a __________, __________ group, and a
nitrogen base.
Function:
–___________________ information.
–________________ proteins.
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Bonds break and form during chemical reactions.
•Chemical reactions change substances into different ones by __________
and ___________ chemical bonds.
–___________ are changed during a chemical reaction.
–___________ are made by a chemical reaction.
•Bond energy is the amount of energy that ______________.
–Energy is _______________ bonds.
–Energy is ___________ when bonds form.
•A reaction is at _______________ when reactants and products form at the
same rate.
Reversible reaction (can occur in both directions)
•Also depending on _________________
Draw the chemical equation.
•When CO2 concentration is high, the reaction moves to the…
…___________ & ___________ H2CO3
•When CO2 concentrations is low, the reaction moves to the …
… __________ & _____________ H2CO3
“Why is concentration important in chemical reactions?”
Answer:
Chemical reactions release or absorb energy.
•___________________ is the amount of energy that needs to be absorbed
to start a chemical reaction.
•__________________reactions release more energy than they absorb.
–Reactants have ___________ bond energies than products.
–___________________________ by the reaction.
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Draw the graph of an exothermic reaction. Label the reactant & product.
•__________________ reactions absorb more energy than they release.
–Reactants have ____________ bond energies than products.
–____________________ by the reaction to make up the difference.
Draw the graph of an endothermic reaction. Label the reactant & product.
“How is activation energy related to bond energy?”
Answer:
A catalyst lowers activation energy.
•_________________ are substances that speed up chemical reactions.
–decrease ___________________________
–increase _____________________
Enzymes allow chemical reactions to occur under tightly controlled
conditions.
•_______________ are catalysts in ____________ things.
–Enzymes are needed for almost __________________.
–Most enzymes are _________________.
•________________ in homeostasis can prevent enzymes from functioning.
–Enzymes function best in a __________________ of conditions.
–Changes in temperature and pH can ____________________ bonds.
–An enzyme’s function depends on its _______________.
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•Enzyme structure & function:
–Altered enzyme structure ____________ the enzyme from
functioning properly.
–Enzymes structure only allows certain reactants to _________ to
enzymes.
•An enzyme’s structure allows only _____________________ to bind to the
enzyme.
–_______________
–_______________
•Substrates:
–______________ acted upon by an enzyme
–__________ to enzyme’s active sites
•The ___________________ model helps illustrate how enzymes function.
–substrates _______________
–_________ in substrates _____________
•Lock-and-key model:
–Only particular substrates (reactants) will bind to _______________.
–When bound, enzymes weaken bonds within substrates & ________
____________________.
Draw the 3 steps of the lock-and-key model
“What are 2 functions of catalysts in chemical reactions?”
Answer:
“How does the structure of the enzyme affect its function?”
Answer:
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