Download presentation
Presentation is loading. Please wait.
1
Chapter 2 CHEMISTRY
2
Matter Composed of atoms Atoms have 3 parts Protons Neutrons Electrons
Positive charge; in nucleus Neutrons No charge; in nucleus Electrons Negative charge; move around nucleus + – 2 Protons Neutrons Electrons Mass number = 4 2e– Electron cloud Nucleus
3
Matter Number of protons = number of electrons so atoms are neutral
Atomic number = number of protons Elements Consists entirely of 1 type of atom
4
Isotopes Atoms of same element but have different numbers of neutrons
Identified by mass number All isotopes have same chemical properties because they have the same number of electrons Radioactive isotopes Unstable nuclei that break down
5
Compounds Substance made up of 2 or more elements
Properties of elements in compound change once combined
6
Chemical Bonds What holds atoms together in compounds 2 Types Ionic
Covalent
7
Sodium chloride (NaCl)
Ionic Bonds When electrons are transferred Creates positive & negative ions Positive Element that lost electrons Negative Element that gained electrons Attraction between ions is what creates bonds Transfer of electron Na Sodium atom Cl Chlorine atom Na+ Sodium ion Cl– Chloride ion Sodium chloride (NaCl) Na Cl + –
8
Covalent Bond When electrons are shared Single bond Double bond
sharing 2 electrons Double bond sharing 4 electrons Molecules are created by atoms in covalent bonds smallest units of compounds
9
Hydrogen Bonds Attraction between polar molecules Van der Waals force
Polar molecules have one end that’s slightly positive & one end that’s slightly negative Van der Waals force Force of attraction between the molecules Weaker bonds Form lots when they occur
10
Water & Polarity What is polarity? Result of polarity
Caused by uneven distribution of elections between the hydrogen & oxygen in water Result of polarity Electrons spend more time around oxygen so that end tends to be slightly negative Hydrogen end is slightly more positive because of this (–) (+) O H
11
Cohesion vs. Adhesion Cohesion Adhesion
when water molecules are attracted to each other (beading of water) Adhesion water is attracted to different molecules like glass
12
Mixtures Mixture is when 2 or more elements are physically mixed together but not chemically combined Ex.- sand & sugar mixed together 2 types of water mixtures solutions suspensions
13
Solutions Ions dispersed in water
Ex.- salt & water All components are evenly distributed Solute substance being dissolved Solvent substance that does dissolving
14
Suspensions When material doesn’t dissolve Breaks into small pieces
15
Acids, Bases, & pH pH scale Acids Bases Buffers
measure amount of hydrogen ions 0-7 is acidic (more hydrogen ions) 7-14 is basic (less hydrogen ions) Acids compounds that form hydrogen ions (H+) in solution Bases form hydroxide ions (OH-) in solutions Buffers weak acids/bases that react with strong ones to change pH
16
Chemical Reactions Changes 1 set of chemicals into another
Process involves breaking old bonds & creating new Reactions that release energy are spontaneous Reactants Products 4H + O H2O 2H2O H + O2
17
Chemical Reactions If a reaction absorbs energy, it can’t occur without an energy source Organisms need energy source to carry out reactions Activation Energy Energy needed to start a reaction
18
Enzymes Catalysts speed up reaction rates by lowering activation energy Enzymes are biological catalysts in cells Specific for a reaction
19
Enzyme Action Enzyme-substrate complex
Enzymes provide the site where reactants can be brought together This reduces energy needed Reactants are called substrates Substrates bind to active site on a protein/enzyme and sites are specific to certain substances
20
Enzyme Regulation Enzymes work best at different pH levels
Affected by temperature Turned off & on
21
Carbohydrates Lipids Proteins Nucleic Acids
Type of Macro Structure Function Examples Carbohydrates Sugars-Glucose/Fructose Monosaccharide-1 Sugar Di Saccharide-2 Sugars Polysaccharide-Many Starch-Storage in plants Glycogen-Storage in Humans Store Energy Main fuel Source for cells Glucose Fructose Sucrose (2 Sugars) Pasta, Grains, Snickers, Fruits Lipids Fatty Acid Chains Triglyceride, Phospholipids, Steroids, Waxes Store energy Protection Hormones Oils, Butter, Tree Nuts, Avocado Proteins Amino Acids (20 different) Dipeptide-2 AA Polypeptide – many AA Primary, Secondary, tertiary, Quaternary Structural Defense-antibodies Signaling-hormones Meats Tree nuts Yogurt Nucleic Acids Pentose Sugar, Phosphate Group, Nitrogenous base DNA – Dbl Stranded, cytoplam RNA – Single Strand, nucleus and cytoplam Store genetic Info CODES FOR PROTEIN DNA RNA
23
Carbon Compounds Carbon forms strong covalent bonds & is a versatile element Monomers Small molecules Building blocks for making larger molecules Polymers Monomers joined together through polymerization Macromolecules Large molecules Very big polymers 4 types of macromolecules Carbohydrates, proteins, lipids, & nucleic acids
24
Carbohydrates Sugars Made up of carbon, hydrogen, & oxygen in a 1:2:1 ratio Main source of energy for living things
25
Carbohydrates All three are made of Carbon, Hydrogen, and Oxygen
Monomers – Monosaccharides Two monosaccharides – Disaccharides Many monosaccharides - Polysaccharides
26
Carbohydrates Monosaccharides Polysaccharides
simple sugars (monomers for carbs) Ex. glucose, galactose, fructose Polysaccharides made up of many monosaccharides Glycogen Storage form of glucose in animals - Starch Storage for of glucose in plants Cellulose found in plant cell walls, what makes them rigid
27
Lipids Not water soluble Made from carbon, hydrogen, & oxygen
Fats, oils, & waxes Store energy for long term or make water-proof coverings Made from glycerol joining with fatty acids
28
Lipids Lipids Made of glycerol and three fatty acid chains Saturated
All hydrogen atoms present on chains and straight Unsaturated Missing hydrogen atoms and chains bent
29
Proteins Made up of nitrogen, carbon, hydrogen, & oxygen
Amino acids are monomers 20 different types of amino acids
30
Proteins Proteins Monomers – Amino Acids Two Amino Acids– Dipeptides
Made of amino group, carboxyl group, and variable group Two Amino Acids– Dipeptides Many Amino Acids- Poly peptides
31
Proteins DNA has the instructions to make proteins
Each protein has a specific role control reaction rates regulate cell processes form bone & muscle transport substances fight disease
32
Nucleic Acids C T A G Base pair Contains hydrogen, oxygen, nitrogen, carbon, & phosphorus Store & transmits hereditary/genetic information 2 types DNA & RNA
33
Nucleic Acid Monomer is a nucleotide 3 parts to a nucleotide
5 carbon sugar phosphate group nitrogen base
34
What are the main nutrients found in food
What are the main nutrients found in food? What role do basic nutrients play in the function of the human body? Carbohydrates Fiber – Helps regulate digestion Sugar – Provides energy Protein – provides essential molecules for structure and support Fat Saturated – unhealthy, solid fat, with straight fatty acid chains Unsaturated – healthy, liquid fat, with bent fatty acid chains Cholesterol – important molecule for cell membranes and cell communication, but too much leads to heart disease Calories – amount of energy in food Sodium – amount of salt in food, leads to high blood pressure Vitamins – C- healing, K – blood clot, A – Retina health, D – bone growth Minerals – Calcium – bone growth, Iron – carrying oxygen in blood
Similar presentations
