Define, in your own words: Atom Element Proton Neutron Electron
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
Same element differs in the number of neutrons in the nucleus and weight. Carbon has 2 common isotopes Carbon-13 and Carbon-14
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/res ource/nvhe.sci.chemistry.decay/radioac tive-decay-of-carbon-14/
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 attraction Covalent – sharing of electrons
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
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 Molecules – contain carbon Carbohydrates, proteins, lipids Inorganic Molecules – do not contain carbon Most important molecule is 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 – 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
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
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
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.
^ Dehydration Synthesis -remove water, make bigger molecules < Hydrolysis – add water, break down molecules
Monosaccharide – one carbon ring. Ex: Glucose, Fructose Dissaccharide – two carbon rings. Ex: sucrose Polysaccharide – three or more carbon rings. Ex: starch, cellulose
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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
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
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)
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
Macromolecules made up of 20 different Amino Acids Amino acids are arranged as follows Central carbon atom An amino group An R Group
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
The sequence of amino acids found in a protein is that protein’s __________ structure a. primaryb. secondary c. tertiaryd. quaternary Why is it possible for humans to digest starch but not cellulose? a. starch is made of glucose molecules but cellulose isn’t b. Starch comes from plants but cellulose doesn’t c. The glucose units found in cellulose are linked differently than those in starch
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.
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