Chapter 2. Basic Chemistry Define, in your own words: Atom Element Proton Neutron Electron.
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Transcript of Chapter 2. Basic Chemistry Define, in your own words: Atom Element Proton Neutron Electron.
CHEMISTRY OF LIFEChapter 2
LESSON 1Basic Chemistry
DO NOW
Define, in your own words:
• Atom• Element• Proton• Neutron• Electron
Elements and Atoms
• All matter is made up of substances called elements.• Only 92 naturally occurring elements• Body is composed of only a few elements
• Carbon• Nitrogen• Oxygen • Hydrogen• Phosphorous• Calcium
• Atoms – smallest unit of an element• Made up of:
• Protons – + charge, nucleus of atom• Neutrons – 0 charge, nucleus of atom• Electrons – ( - ) charge, orbit around nucleus
Isotopes
• Same element differs in the number of neutrons in the nucleus and weight.
• Carbon has 2 common isotopes• Carbon-13 and Carbon-14
Radioactive Isotopes
• As isotopes break down they release energy in the form of rays and subatomic particles
• Carbon-14 is a common Radioactive isotope• Unstable and breaks down over
time
http://www.pbslearningmedia.org/resource/nvhe.sci.chemistry.decay/radioactive-decay-of-carbon-14
/
Molecules and Compounds
Molecule – 2 or more of the same atoms bonded together to form a chemical unit
Compound – 2 or more different atoms bonded together to form a chemical unit.
Types of Bonds:Ionic – created by an electrical
attractionCovalent – sharing of electrons
Bonds
• Polar Covalent – electrons spend more time with the more electronegative element
• Non-polar Covalent – equally shared electrons
Chemical Bonds
Double Bond – 2 pairs of electrons are shared
Triple Bond – 3 pairs of electrons are shared
In class assignment
• Elements in Living Things Coloring Handout
Homework
• Study Questions pg 39 # 1-4
LESSON 2Water, Acids and Bases
Do Now
• Have your homework from last night out on your desk for me to check!
• What is the difference between ionic and covalent bonds?
• What elements make up the human body?
Organic vs Inorganic
• Organic Molecules – contain carbon• Carbohydrates, proteins, lipids
• Inorganic Molecules – do not contain carbon• Most important molecule is WATER
Water• Polarity and Hydrogen bonding gives
water all of it’s unique and beneficial properties.• Solvent for polar molecules• Cohesive – water molecules stick
together• Adhesive – water molecules stick to
other surfaces• High Specific Heat Capacity/Heat of
vaporization
Video
Acids and Bases
• Acids – substance that separates in water• Bases – takes up hydrogen ions or
releases hydroxide ions
• pH scale – ranges from 0-14, indicates the acidity and basicity of solutions
Acids and bases
pH scale
Acids and Bases
It’s important to maintain body fluid in a narrow pH range. (about 7.4)
Acidosis – pH value drops below 7.35 Occurs when kidneys and lungs can’t keep your pH balanced
Alkalosis – pH value rises above 7.45 Occurs when there is high levels of bicarbonate in your blood Excessive loss of acid Low carbon dioxide level
Buffers – help to keep pH in a normal range they are chemicals or pairs of chemicals that take up excess
hydrogen ions or hydroxide ions
Content Check
• Depending on what you’ve eaten recently, the pH of your urine can vary from 5 to 8.• Which is more acidic – urine at pH 5 of
pH 8
Electrolytes
A substance that releases ions when put into water
These ions can conduct an electrical current
Electrolyte balance is important for good health because it effects the functioning of vital organs.
Homework
• Study Guide Questions pg 39 # 6-7
LESSON 3Molecules of Life
Do Now
• Macromolecules Handout• Hand in Properties of Water Lab
Macromolecules
Molecules of Life
^ Dehydration Synthesis- remove water,
make bigger molecules
< Hydrolysis – add water, break down molecules
Carbohydratesquick, short-term cellular energy
• Monosaccharide – one carbon ring. Ex: Glucose, Fructose • Dissaccharide – two carbon rings. Ex: sucrose• Polysaccharide – three or more carbon rings. Ex: starch,
cellulose
Do NowSeptember 30, 2014
Hand in your homework! Take out your notes & be ready to work!
Carbohydrates
Made up of C, H, O in a 1:2:1 ratio Glucose – used as an immediate source
of energy Maltose is 2 glucose molecules, found in
alcoholic beverages Sucrose – glucose & fructose together,
this is table sugar Lactose – glucose and galactose, this is
found in milk
Polysaccharides
Means many sugars, LONG chains of sugar molecules
Starch – energy storage in plants Glycogen – energy storage in animals Cellulose – what cell walls are made up of
We cannot digest this, this helps to scrape the walls of our intestines
Common Polysaccharides
Lipidslong-term energy storage, part of membranes
Saturated Fats - have only single covalent bonds, solid at room temperature. Ex: Butter (usually of animal origin)Unsaturated Fats – have double/triple bonds, liquid at room temperature. Ex: Oils (usually of plant origin)
Lipids
Made of a glycerol molecule and a triglyceride, or three fatty acids.
Can be emulsified – mixed with water, molecules position themselves around a droplet so that their nonpolar ends stick out and the droplet disperse in water
Phospholipids – contain phosphate group, important for cell membranes
Steroids – different structure than fats, back bone of 4 carbon rings, with differing side chains
cholesterol is an example of a steroid
Proteinswide range of functions
• Macromolecules made up of 20 different Amino Acids • Amino acids are arranged as follows
• Central carbon atom• An amino group• An R Group
Structure of Proteins
Composed of amino acids When two amino acids join, called a dipeptide Polypeptide contains 3 or more amino acids
Primary Structure Sequence of Amino acids in a polypeptide
Secondary Structure Coiling or folding of the protein
Tertiary Structure Hydrogen, ionic, covalent bonding all occur in polypeptides
Quaternary Structure Protein that has more than 1 polypeptide, arrangement of
individual polypeptides When proteins are exposed to extreme heat and pH
they denature, and this is irreversible
Protein Structure
Content Check
The sequence of amino acids found in a protein is that protein’s __________ structure
a. primary b. secondaryc. tertiary d. quaternary
Why is it possible for humans to digest starch but not cellulose?a. starch is made of glucose molecules but cellulose
isn’tb. Starch comes from plants but cellulose doesn’tc. The glucose units found in cellulose are linked
differently than those in starch
Enzymes
Protein catalysts Enable particular metabolic reaction to occur
at the body’s normal temperature Energy activation – energy needed to
start a reaction Substrates – reactants in an enzymatic
reaction Enzymes are very specific this is caused
by the shape and chemical composition of it’s active site.
Enzyme Substrate Complex
Nucleic Acidscontain hereditary information
• Two Classes:• RNA – ribonucleic acid, bases are AUGC (codes for proteins)• DNA – deoxyribonucleic acid, bases are ATGC (makes up
genes)
Nucleic Acids
ATP
Adenosine plus 3 phosphate groups PRIMARY ENERGY CARRIER IN CELLS Cells require a constant supply
continually break down glucose Some uses:
Synthesizing macromolecules Muscle contraction Conduction of nerve signals
In Class Assignment/Homework
• Macromolecules Worksheet #2