Wack Anatomy Chapter 2

chemistry

studies matter and its interaction

matter

anything that has mass and takes up space

what forms can matter be in

solid, liquid, or gas

mass

the weight of something in relationship to gravity

elements

basic substances that cannot be further broken down by physical means

how many natural elements are there

92

what elements are 95% of the body made of

Carbon, hydrogen, oxygen, and nitrogen

atoms

small particles of elements

what are the four things that make up an atom

the nucleus, electrons, protons, and neutrons

nucleus

center

electrons

negative charge

protons

positive charge

neutrons

no charge

what is always equal in an electrically neutral atoms

the number of protons always equals the number of electrons

atomic number

the number of protons in the nucleus

atomic weight

the number of protons plus the number of neutrons

isotopes

have different numbers of neutrons and they have different mass numbers

electron shells

orbit pathways of electrons around the nucleus

how many electrons does the first second and third shell of the electron shell hold

1st holds 2 2nd holds 8 3rd holds 18

chemical bonding

makes atoms with unfilled outer electron shells more stable

molecules

two or more of the same atoms combined by sharing electrons

compounds

two or more different atoms combine

ionic

electrons are transferred (stolen)

cations

ions with a (+) charge

anions

ions with a (-) charge

covalent bonds

electrons are shared between atoms

explain single double and triple covalent bonds

single- one pair of electrons shared (H-H) double- two pairs of electrons are shared (O=O) triple- three paired of electrons are shared (N=N)

nonpolar covalent bond

electrons are shared equally creating a neutral atom

polar covalent bond

electrons are unequally shared causing one end to be slightly positive and the other to be slightly negative like water

hydrogen bonds

weak attraction between hydrogen and other molecules (due to polar covalent bonding)

what do hydrogen bonds create

surface tension on water

what do chemical reactions do

they form or break bonds

reactants

the substances on the lefts of the yield arrow

products

the substances on the right side of the yield arrow

decomposition

the reactants break down into simpler products AB-> A+B

hydrolysis

reactants that add water to the reactants

catabolism

decomposition reactions that release energy

synthesis

two or more reactants form a product(s) A+B ->AB

dehydration synthesis (condensation)

reactions that remove water molecules

anabolism

reactions that synthesize new compounds

exchange reactions (displacement)

parts of different molecules trade places AB + CD-> AD + BC

reversible reactions

products can become reactants or reactants can become products A+B

equilibrium

the balance of synthesis and decomposition reactions

metabolism

all the chemical reactions in the body

enzymes

proteins that help chemical reactions happen

what do enzymes lower

the activation energy needed

activation energy

the amount of energy necessary for a reaction to begin

catalysts

atoms of molecules that change the rate of a chemical reaction without being consumed or changed in the process

exergonic reactions

those that release energy

endergonic reactions

those that absorb energy

inorganics

substances without carbon

nutrients

essential elements and molecules gotten from the diet

metabolites

made or broken down by our bodies

organics

contain carbon

water

2/3 to 3/4 of body weight

4 properties of water

1. an essential reactant in chemical reactions of living systems 2. high heat capacity (absorbs and transports heat) 3. good solvent (dissolves both organic and inorganic substances solvent does the dissolving) 4. good lubricant

solutions

mix of solvent and solutes

ionization (dissociation)

ionic bonds break and ions attach to polar water molecules

what do ionic solutions cunduct

current

pH

the measurement of the concentration of hydrogen ions (H+) in a solution

what does pH stand for

percent hydrogen

what does the pH scale range from

0 to 14

neutral (pure water) on the pH scale is what

7

what does each step on the pH scale represent

a factor of 10 in the concentration of H+ ions

what's the difference of the H+ ions between 4 and 5 on the pH scale

10 times

what part of the pH scale is the most extreme

the ends

acids

any compound that forms hydrogen (H+ ions) in a solution have pH values less than 7

salts

ionic compounds composed of any cation except H+ and anion except OH-

how are salts held together

by ionic bonds

what do salts do in water

dissociate

electrolytes

a substance that decomposes into ions and conducts electricity in a solution

buffers

weak acids or weak bases that can react with strong acids or strong bases to prevent sudden changes in pH

4 things about carbohydrates

1. contain C H and O in a 1:2:1 ratio 2. can form chains or rings 3. include sugars and starch 4. are primary energy sources

monosaccharides

simple sugars like glucose (blood sugar)

disaccharides

two monosaccharides joined like sucrose (table sugar)

how are disaccharides formed

by dehydration synthesis

how are disaccharides broken down

by hydrolysis

polysaccharides

large molecules connected together

examples of polysaccharides

starch, cellulose, and glycogen

starch

from plants and is broken down into simple sugars

cellulose

from plant cell walls and is not digested by humans

glycogen

animal starch that s stored in the liver (short term storage)

4 things about lipids

1. contain C H and O 2. most are insoluable in water 3. form structural components of cells 4. energy reserves (6X carbos)

fatty acids

long chains of carbon with hydrogen attached to a carboxyl group (-COOH)

saturated fats

all single C to C bonds which allows each carbon to be attached to as many hydrogens as possible

3 things about saturated fats

1. usually solid at room temperature 2. most come from animal products 3. are referred to as "bad" fats

unsaturated fats

contain one or more carbon to carbon bonds (C=C)

3 things about unsaturated fats

1. usually liquid at room temperature 2. most come from eating plant material 3. are called "good" fats

polyunsaturated fats

contain double bonds

fats

chains made of glycerol and fatty acids

triglycerides

fats with glycerol and 3 fatty acids

steroids

large lipids made of three rings

cholesterol

steroid needed for cell membranes and hormones

phospholipids

made of two fatty acids, a glycerol, and a phosphate group (PO4)

what are the parts of phospholipids

the phosphate end is soluable in water and forms the hydrophilic head end and the fatty acid end is insoluble in water and forms the hydrophobic tail end

proteins

most numeroud organic compound in the body

what do proteins contain

C, H, N, O, P, S

what are the 7 functions of proteins

support, movement, transport, metabolic regulation, coordination and control, defense, and buffering

protein structure

made of smaller building blocks called amino acids

how many different amino acids are there

20