Title: THE CHEMISTRY OF LIFE
1THE CHEMISTRY OF LIFE
22.1 The Nature of Matter
- The basic unit of matter is an atom
- Atoms cannot be broken down
- Atoms are made up of subatomic particles
- Protonspositively () charged
- Neutronsno charge
- Electronsnegatively (-) charged
3Subatomic Particles
- Nucleus is made up of protons plus neutrons
- Protons and Neutrons also make up the mass of an
atom. - Electrons orbit the nucleus.
4Nitrogen (7P, 7N, 7E)
5Elements and Isotopes
- Elements are a pure substance that consist of
just one kind of atom - Examples
- Carbon C
- Hydrogen H
- Sodium - Na
6Elements and Isotopes
- Isotopes are atoms of the same element with a
different number of neutrons - Radioactive Isotopes- nuclei is unstable and will
break down at a constant rate. - Carbon-14 (6P, 6E, 8N) radioactive
- Carbon-13 (6P, 6E, 7N) nonradioactive
- Carbon-12 (6P, 6E, 6N) nonradioactive
- Used for determine age of rocks and fossils,
treat cancer, kill bacteria, or as labels in
organisms.
7Chemical Compounds and Bonds
- Compounds are substances formed by 2 or more
elements. - Ex. Water H2O, Carbon Dioxide CO2, and Salt-
NaCl - A molecule is the smallest unit of most
compounds. - There are two type of chemical bonds
- Ionic Bonds one or more electrons are
transferred from one atom to another. - Covalent Bonds electrons are shared between
atoms.
8 Ionic Bond
Sodium atom (Na)
Chlorine atom (Cl)
Sodium ion (Na)
Chloride ion (Cl-)
Transfer of electron
Protons 11 Electrons -11 Charge 0
Protons 17 Electrons -17 Charge 0
Protons 11 Electrons -10 Charge 1
Protons 17 Electrons -18 Charge -1
9Covalent Bond
Bonds can exist as Single, double, or triple
bonds
10Van der Waals Forces
- An attraction that forms between oppositely
charged regions of nearby molecules. - Ex. Geckos foot and a wall
- Charge is not as strong as ionic or covalent
bonds.
112-1 Section Assessment
- Describe the structure of an atom.
- Why do all isotopes of an element have the same
chemical properties? In what ways do isotopes of
an element differ? - What is a covalent bond? An ionic bond?
- What is a compound? How are compounds related to
molecules?
122-2 Properties of Water
- Water is a polar molecule. That is, it has an
uneven distribution of e- between the oxygen and
hydrogen atoms
13Hydrogen Bonds
- Not as strong as covalent or ionic bonds.
- Water is cohesive and adhesive
- Cohesion- attraction between molecules of the
same substance - Ex. Water molecules
- Adhesion- attraction between molecules of
different substances - Ex. Water and glass
14Solution and Suspensions
- Mixture a material composed of two or more
elements or compounds physically mixed -
- Ex air, sand and water, salt and water
15Solution
- Solution mixture where particles are evenly
distributed - two parts
- -solute sub. that is dissolved
- -solvent does the dissolving
16NaCl Solution
Cl-
Cl-
Na
Na
Water
Water
Salt is an ionic compound. When placed in
Water, water separates and ions.
17Suspensions
- Suspension mixture of water and substances that
do not dissolve - -ex. sand and water, blood
18Acids, Bases, and pH
- H2O ? H OH-
- Water ? Hydrogen ion Hydroxide ion
- acid contain higher concentrations of H ions
than pure water - base contain lower concentrations of H ions
than pure water
19pH Scale
- Used to indicate the concentration of H ions in
a solution. - 0?14/Acid?Base
- 7 is neutral
202-2 Section Assessment
- Use the structure of a water molecule to explain
why its polar. - Compare acidic and basic solutions in terms of
their H ion and OH- ion concentration. - What is the difference between a solution and a
suspension?
212-3 Carbon Compounds
- Carbohydrates- Sugars and Starches
- Lipids- Fats and Oils
- Nucleic Acids- Nucleotides
- Proteins- Amino Acids
carbons structure has four valence electrons a
carbon atom can bond to other carbon atoms to
form chains or rings
22Carbohydrates
- Function- Main energy source for living things.
- Serves as a structural purpose in plants and some
animals.
Starch
Glucose
23More Carbs
- Monosaccharides- single sugar
- Ex. Glucose, galactose, and fructose
- Polysaccharides- many sugars
- Ex. Starches, glycogen, and cellulose
24Lipids
- Lipids are made mostly from carbon, hydrogen, and
oxygen - Function- Store energy
- -some examples are fats, oils, and waxes
- -saturated no double bonds-butter
- -unsaturated has double or
- triple bonds olive oil
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26Nucleic Acids
- nucleic acids contain carbon, hydrogen, oxygen,
nitrogen, and phosphorus - Nucleotides consists of
- 5-Carbon sugar
- Phosphate group
- Nitrogenous base
27Nucleic Acids
- Function of nucleic acids store and transmit
hereditary or genetic information - two types DNA and RNA
28Proteins
- proteins contain carbon, hydrogen, oxygen,
nitrogen - -building blocks amino acids
- - 20 different kinds
29Protein Structure
Amino acids
30Proteins
- Function of proteins
- control rate of chemical reaction
- regulate cell processes
- form bone and muscle
- transport substances
- fight disease
312-3 Section Assessment
- Name four groups of organic compounds found in
living things. - Describe at least one function of each group of
organic compounds.
322-4 Chemical Reactions and Enzymes
- chemical reaction process that changes one set
of chemicals into another - -two parts
- reactants - enter reaction
- products - produced by reaction
an example of a chemical reaction CO2 H2O ?
H2CO3 carbon dioxide water yields carbonic acid
33Enzymes
- catalyst substance that speeds up a chemical
reaction -
- -enzymes are biological catalysts
- -enzymes speed up chemical reactions in cells
34Enzyme Action
- for a chemical reaction to take place, the
reactants must collide with each other to break
the bonds - -substrates are what the enzyme breaks down or
builds up - -the site where an enzyme and substrate meet is
called the active site
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