Chapter 2 - Intro to Chemistry Flashcards
Compound
substance composed of 2 or more elements in a fixed ratio
Mixture
substance composed of 2 or more components physically blended together; not a fixed ratio
Solution
homogeneous (evenly mixed) mixture of gases, liquids or solids
Solvent
dissolving medium, substance present in the greatest amount
Solute
substance that is dissolved, substance present in a smaller amount
Colloid or Emulsion
heterogeneous (unevenly mixed) mixture
Suspension
heterogeneous mixture, solutes tend to settle out and are visible
Organic compounds
CARBON-based compounds that are usually LARGE and COMPLEX
Inorganic compounds
compounds that usually LACK CARBON and are SIMPLE
Base
a substance that removes H+ ions from a solution
Acid
a substance that releases H+ ions into solution
Buffers
weak acids or bases that help minimize changes in pH
Dehydration synthesis
a synthesis reaction in which water is removed and a covalent bond is formed; results in something bigger
Hydrolysis
a decomposition reaction in which water is added and a covalent bond is broken
Exchange reaction
reactions in with both synthesis and decomposition occur
Catalyst
a substance that increases the rate of a chemical reactions
Enzyme
biological catalyst: a protein that speeds up chemical reactions
Isomers
substances with the same molecular formula but different arrangement of atoms (so slightly different properties)
Functional groups
groups of atoms that participate in chemical reactions; groups of organic compounds attached to carbon skeleton that allow it to participate in chemical reactions.
Metabolism
the sum of all the chemical reactions that take place in the body; all synthesis, decomposition & exchange reactions taking place in body
Atomic #
of protons in nucleus
Mass #
sum of its protons and neutrons
of Electrons
of protons
Major elements that make up over 96% of the human body:
- Oxygen - O
- Carbon - C
- Hydrogen - H
- Nitrogen - N
Lesser elements - Make up about 3.9% of the body:
- Calcium - Ca
- Phosphorous - P
- Sulfur - S
- Potassium - K
- Sodium - Na
- Chlorine - Cl
- Magnesium - Mg
- Iodine - I
- Iron - Fe
3 Chemical bonds:
- Ionic bonds - transfer of electrons
- Covalent bonds - can form molecules
- Hydrogen bonds - weak attraction that exists between polar molecules
2 Kinds of Molecules
- Polar molecule - electrons not shared equally; the nucleus of one atom attracts the shared electrons more strongly than the nucleus of the other atom.
- Nonpolar molecules - electrons are evenly distributed; one atom does not attract the shared electrons more strongly than the other atom
3 Kinds of Mixtures:
- Solution - homogeneous (evenly mixed); dissolves in solution completely; clear & transparent
- Colloid - particles are large enough to scatter light; cloudy, translucent or opaque; somewhere between liquid & solid
- Suspension - particles so large they fall out of the solution & sink to the bottom
Examples of Solution
- Salt (solute) dissolved in water (solvent);
- sugar dissolved in water;
- air - mixture of forming gases - N, H2O, O
Examples of Colloid
- Jello (dissolves in water, but cloudy, proteins scatter light;
- cytosol - fluid inside cells (water, proteins - consistency of jello)
Biological example of Suspension
blood - blood settles when it sits, red blood cells sink to the bottom, & plasma floats on top & white blood cells & platelets are in the middle
Chemical Reactions
rearrangements of matter (mass); these rearrangements make new substances; matter is not destroyed or created, it’s just rearranged
Reactant
Starting material before reaction occurs
Product
what is formed as a result of chemical reaction
3 Kinds of Chemical Reactions
- Synthesis reactions - chemical bonds are formed, larger molecule results
- Decomposition reactions - chemical bonds are broken, small molecules or atoms result
- Exchange reaction - chemical bonds are formed & broken & something bigger & smaller results; both synthesis & decomposition occur
Example of Syntheses reactions
Amino acids (link many together) — Protein molecule (larger molecule)
Example of Decomposition reactions
Glycogen — Glucose molecules
Example of Exchange reactions
Glucose + ATP — Glucose Phosphate + ADP:
Synthesis happens when Glucose forms into Glucose Phosphate;
Decomposition happens when ATP forms into ADP
Most important Synthesis reaction taking place in body
Dehydration Synthesis - involves loss of water; removal of water causes a covalent bond–how we build large molecules in body
Most important Decomposition reaction taking place in body
Hydrolysis - add water to break down things in the body; main way we break down things in body; digestive system
Things to speed up chemical reactions:
- Temperature - if temp increases, atoms & molecules move faster
- Concentration - of reactants; add more particles–increase concentration; more likely to bump into each other
- Particle size - small particles move faster, large particles sluggish; decrease particle size
- Catalysts - introduce a catalyst to increase chemical reaction (i.e enzymes)
Biological Catalyst
Enzymes - proteins (made inside our cells); specific–target 1 specific chemical reaction; can be reused; presence & absence of enzymes determine whether chemical reactions take place in the body
Biochemistry
study of chemical reactions & chemical composition of living things
Chemical composition of living things
chemicals in body reactive–combine with other elements in body to form compounds
Examples of organic compounds
Mainly food molecules–proteins, carbs, lipids (fats), DNA (hold nucleic acids
Examples of inorganic compounds
Water, salts, acids & bases
Examples of organic compounds
Mainly food molecules–proteins, carbs, lipids (fats), DNA (hold nucleic acids) & ATP
Examples of inorganic compounds
Water, salts, acids & bases
Properties of Water (Inorganic compound):
- High heat capacity
- High heat of vaporization
- Universal solvent
- Reactant
- Cushioning
High heat of vaporization (property of water)
takes a lot of heat to change water into gas; affects how our body is cooled down
High heat capacity (property of water)
can hold a lot of heat without changing temp; body temp fairly constant
Universal solvent (property of water)
dissolving medium; water dissolves a lot of substances in body bc most of molecules in body are polar: polar molecules dissolve other polar molecules; why chemical reactions take place in body
Reactant (property of water)
water PARTICIPATES in chemical reactions
Cushioning (property of water)
fluid that surrounds brain & spinal cord (CSF-cerebrospinal fluid)–mostly water
O
selfish; holds electrons tightly; when electrons are shared, pulled more to O side–negatively charged
H
partial positive;
Hydrogen bonds
weak attractions between polar molecules such as water
Salts (inorganic compound)
ionic compound when dissolved in water, doesn’t release H; are electrolytes
Ionic bonds
electrons transferred from one atom to another which causes resulting atoms to be charged; always forms compounds
electrolytes
substance that conducts electricity in water; release charged particles
Na+
important for water balance; most abundant ion in body; water attracted to ions; the more sodium in body, the more water; too much Na+ = too much water in body
Na+ and K+
important in generating electrical systems & running of nervous system; how we control our body
Ca++
important for skeletal system; essential for muscle contractions; plays role in blood clotting
Acid
always releases H+ ions; electrolytes
Bases
- usually releases OH- (hydroxyl ion) solution
- removes H+ ions that are already in the solution
pH scale
way we measure amounts of H+ ions in solutions; can only be measured if dissolved in a liquid (H2O); scale that tell us if a solution is acidic or basic (alkaline)
’s below pH7
acidic solution; H+ (more hydrogen ions)
’s above pH7
basic solutions; H+ (less hydrogen ions)
decrease pH
more acidic; more H+ in solution
increase pH
more basic; fewer H+ in solution
pH6
10x more H+ than pH7; one pH unit lower means 10x more H+ ions
pH5
100x more H+ than pH7; one pH unit higher means 1/10 less H+ ions
buffer
substances that keep pH fairly constant in body
pH affects proteins & enzymes are proteins so it affects chemical reactions
k
Blood buffer =
carbonic acid (weak acid)-bicarbinate buffer (weak base)
when pH increases
carbonic acid brings it down–adds H+
when pH decreases (too many H+)
bicarbinate removes H+
pH7
neutral; concentration of H+ and OH- are equal (10 to the -7 mol/liter) = .0000001; (ex. pure water–distilled water)
Carbon
has 4 unpaired electrons in its outermost valence shell; can form variety of bonds
Carbon skeleton
framework; chain of carbons or ring of carbons that service framework for organic compounds
Hydroxyl
OH
Carbonyl
C=O
Carboxyl
COOH
Amino
NH2
Sulfhydryl
SH
Phosphate
PO4-2
Hydrogen bond
forms when a hydrogen atom w/a partial positive charge attracts the partial negative charge of neighboring electronegative atom, most ofter larger oxygen or nitrogen atoms. Result from attraction of oppositely charged parts of molecules rather than from sharing of electrons (covalent bonds) or loss/gain of electrons (ionic bonds)
Ionic bonds form
compounds
Covalent bonds result in
molecules
H2O
compound, molecule, polar molecule–slightly lopsided; electrons not shared equally
