1 atom

2 molecule

3 cell

4 tissue

5 organ

6 organ system

7 organism

8 population

9 community

10 ecosystem

11 biosphere

-simplest level of organization

-smallest unit of an element (basic building block of matter)

-Niels Bohr came up with the model of the atom

-contain specific numbers of protons (positively charged particles), neutrons (particles with no charge), and electrons (negatively charged particles)

composed mainly of carbons and hydrogens (ex C6H12O6-glucose)

smallest unit of life capable of reproducing and functioning on its own (ex. neuron-transmits information within the cell)

*cell is where life begins

*the basic structural and functional unit of all living things

composed of an aggregation of two or more cells (ex. muscle)

*these cells must look and function alike

*many types of tissues: epithelium (skin), connective (fat & bone), muscle (skeletal) and nervous (brain)

composed of two or more tissue types (ex. stomach).

*all organs have unique functions

1 nose

2 mouth

3 larynx

4 trachea

5 lungs

-made up of different organ systems

-multicellular (made of many cells)

*exception: bacteria (unicellular)

1 organisms build proteins based on the instructions of DNA

2 organisms reproduce and develop

3 organisms stay alive by way of metabolism

4 organisms sense and respond to changing conditions in their environment

(organisms build proteins based on the instructions of DNA-deoxyribose nucleic acid)

-it is the hereditary material containing genes inherent from parents (ex. genes for eye color and hair color)

-proteins made from amino acids (building blocks). total of 20 amino acids used to make proteins:

important proteins:

*enzymes-speed up chemical reactions

*hormones-regulate cell activity

-DNA transferred to offspring from parents through sexual reproduction, when sperm fuses with the egg producing a zygote (fertilized egg)

-increasing the number of body cells (development)

-by way of metabolism: all the chemical reactions by which the cell acquires and uses energy

*producers: plants and other organisms that make their own food

*consumers: animals and decomposers that must obtain food by capture or breaking down decaying matter

-a stimulus produces change (ex. sunglight, temperature or chemicals)

-receptors on cells trigger change

-homestasis= keeping the internal environment within a range of tolerance

keeping the internal environment within a range of tolerance

*all organisms must maintain this state of biological balance

*organisms have intricate feedback and control mechanisms to maintain homestatic balance.

(ex. sweating to prevent the body from over-heating)

Carolus Linnaaeus

-devised a scheme for classifying organisms based on their similar characteristics

-he designed a two-part name for each species called the scientific name

-part one: Genus (ex. Homo)

-part two: Specific epithet (ex. sapiens)

*binomial name

1. Genus (ex. Homo)

2. specific epithet (ex. sapiens)

organisms of the same domain are the most distantly related in regards to the classification of organisms

1. Archaea

2. Bacteria

3. Eukarya

single-celled organisms that can live in boiling water, freezing desert, sulfur-rich lakes and other harsh conditions (can live water devoid of oxygen)

*unicellular prokaryotes

*no membrane-bound nucleus

-single-celled organisms that live in diverse habitats NOT extreme conditions

*unicellular prokaryotes

(variously adapted to living almost anywhere-water, soil, atmosphere, in/on human body, etc)

*no membrane-bound nucleus

contain plants, fungi, animals and protists

some are single-celled organisms, other are multicellular

*this domain contains some of your most complex organisms

(contains four kingdoms: Protista, Fungi, Plantae, and Animalia)

protists (Protista) range from unicellular forms to multicellular ones

plants (Plantae) are multicellular, photosynthetic organisms

Fungi are the molds and mushrooms

animals (Animalia) multicellular organisms that ingest and process their food

1. species

2. genus

3. family

4. order

5. class

6. phylum

7. kingdom

8. domain

-proposed by Charles Darwin (a naturalist) who noted variations among different organisms (survival of the fittest rule)

variation in hereditary traits (changes in DNA)

-adaptation or evolution: a genetic development that improves how an individual survives and reproduces in its environment

-diversity: variations that accumulate in lines of descent

is a tool used by all scientists to gather facts or data

1. observation

2. hypothesis

-prediction

3. test (experiment)

4. theory

*first step in the scientific method

-observe a natural event in nature using special senses (natural events are called phenomena)

-formulate questions (who, what, why how) in order to look for answers

-do research

*second step in scientific method

-an educated guess or possible answer to question(s) using all known information

-use inductive reasoning (combine isolated facts to develop possible explanation)

Prediction: making a statement about the outcome of the hypothesis is valid (true)

must be testable

*third step in scientific method

-testing the hypothetical statement by designing models, using variables and collecting data (include a control group)

-data analysis will validate or invalidate the hypothesis

-test should be repeated for consistency

-form reports, analyze data and make conclusions based on experiments

*deductive reasoning: "if, then" logic to make a prediction that the hypothesis can be supported by experimentation.

*fourth (last) step of scientific method

-a valid hypothesis becomes a scientific theory

1. solid- ice

2. liquid-water

3. gas-steam

element

(how many occur naturally? how are they represented and where?)

substance composed of one type of atom

-by definition, they cannot be broken down to simpler substances with different chemical or physical properties

-listed in the periodic table

-92 occur naturally; others produced in labs

-denoted by chemical symbols (ex. H-hydrogen)

1. protons

2. electrons

3. neutrons

-positive electrical charge

-found within the atomic nucleus

-atomic number signifies the number of protons in the atom

-a neutral atom will have the same number of protons and electrons

-the atomic mass number is the number of protons and neutrons in the atom

-negative electrical charge

-found rotating outside of the atomic nucleus; they occupy orbitals within various energy levels (=electron shells) near or distant from the nucleus of the atom. the further the orbital from the nucleus-->the higher the energy level

*an orbital is a volume of space where an electron is most likely to be found

*an orbital can contain no more than 2 electrons

-a neutral atom (no charge) will have equal # of protons and electrons

atomic number: number of protons in the atom (located above or to the left of the chemical symbol)

*all atoms of an element have the same number of protons and electrons

atomic mass number: number of protons and neutrons in an atom (located below or to the left of the chemical symbol)

-protons and neutrons have one amu

-electrons have zero amu

atoms with the same atomic number but a different number of neutrons (ex. C12--carbon-12-- has 6 protons and 6 electrons vs C14--carbon-14--has 6 protons and 8 electrons)

radioactive isotopes:

-unstable nuclei (atom tends to rupture)

-emit energy that is dangerous to living things

-used for x-rays, tracers, medical treatment and estimating the age of fossil remains (C14-->carbon dating)

-atoms with unbalanced charges (proton number does not equal the electron number)

-atoms gain or lose electrons

1. postive charged ions:have more protons than electrons (lost electrons)

ex. Na+

2. negative charged ions:have more electrons than protons (gained electron(s))

ex. Cl-

1. ionic bonds

2. covalent bonds

3. hydrogen bonds

forms when electrons are transferred from one atom to another atom

attraction of oppositely charged ions holds the two atoms together in this bond (ex. Na+ + Cl---->NaCl=salt

sodium loses an electron and therefore has a positive charge; chlorine gains and electron to give it a negative charge; when they combine they form salt)

*by losing or gaining electrons, atoms fill outer shells, and are more stable (the octet rule)

covalent bonds

(5 types)

attraction between two atoms that share a pair of electrons

-tend to be stable bonds

-stronger than ionic bonds

-each atom has an octet of electrons in the outer shell

-hydrogen can give up an electron to become a hydrogen ion (H+) or share an electron with another atom to complete its shell with 2 electrons

-bonds between carbon and hydrogen or oxygen tend to be covalent

1. single covalent bonds: one pair of electrons shared

2. double covalent bonds: two pairs of electrons can be shared

3. triple covalent bonds: three pairs of electrons shared

4. nonpolar covalent bonds: two identical atoms share electrons (ex. O2) *sharing of electrons is equal

*electrons are not attracted to either to a greater degree

5. polar covalent bond: two different atoms share electrons (ex. CH4)

*the sharing of electrons is unequal

attraction between polar molecules (forms between water molecules)

arises between a slightly positive hydrogen atom of one molecule and a slightly negative charge of another atom (e.g. oxygen, nitrogen) often on different molecules or separated by some distance

-weaker bonds than covalent or ionic bonds

-indicated with dash line

-hydrogen bonds between and within complex biological molecules (e.g. DNA, proteins) help maintain their proper structure and function

the innermost shell of an atom is complete with 2 electrons

all other shells are complete with 8 electrons

*atoms will give up, accept, or share electrons in order to have 8 electrons in an electron shell

-when atoms absorb energy during photosynthesis, electrons are boosted to higher energy levels.when the electrons return to their original energy level, the released energy is converted into chemical energy(=supports all life on Earth)

-electrons possess energy, and bonds that exist between atoms in molecules therefore contain energy (ionic, covalent, and hydrogen bonds)

attraction of an atom for electrons in a covalent bond

*an oxygen atom is more electronegative than a hydrogen atom

properties of water

(...what kind of molecule is it)

-water is a substance that is essential to life making up most of the cell volume

-it is a polar molecule: (1) oxygen atomis sharing electrons with (2) hyrogen atoms)

-the shape of a water molecule and its polarity makes hydrogen bonding possible

*a polar molecule is attracted to other water molecules, sugars and other polar molecules

*water is hydrophilic (=water loving) to polar molecules

*water is hydrophobic (=water dreading/hating) to nonpolar molecules

**nonpolar molecules such as oil and fats are hydrophobic

*water acts as a heat reservoir (high heat capacity)

*it has temperature stabilizing effects

**evaporation: converting water into gas

*is a universal solvent = has the capacity to dissolve many substances

**solute=substance dissolved in a solvent

*has cohesion: surface tension is not easily broken (water is cohesive)

-temp of liquid water rises and falls more slowely than that of most other liquids

*bc the hydrogen bonds between the water molecules hold more heat

*this protects organisms from rapid temperature changes and helps them maintain homeostatic temperature

-calorie: the amount of heat energy required to raise the temperature of one gram of water 1C

"water loving"

ionized or polar molecules attracted to water are hydrophilic

"water fearing"

nonionized and nonpolar molecules that cannot attract water are hydrophobic

cohesion: allows water to flow freely without molecules separating

*water has high surface tension and is relatively difficult to break through at its surface (i.e. skipping rocks)

adhesion: ability to adhere polar surfaces; water molecules have positive and negative poles

a substance that releases hydrogen ions (H+) when dissolved in water

*types of acidic solutions: pH below 7

lemon juice

vinegar

coffee

HCL stomach acid

a substance that releases hydroxide ions (OH-) when dissolved in water

*types of basic or alkaline solutions: pH above 7

sodium hydroxide (lye)

seawater

baking soda

(chemical equation) shows the production of salt from the chemical combining of an acid and base

hydrochloric acid                   sodium hydroxide       sodium chloride              water

HCl       +      NaOH---->NaCl    +    H20

pH scale

-range of pH scale

-hydrogen ion concentration=pH measurement?

-pH of 7?

-pH below 7?

-pH above 7?

-pH range of body fluids and blood

-changes in pH?

measures the concentration of hydrogen & hyrdroxide ion in a solution (indicates the acidity and basicity of a solution)

*measuring scale range from 0-14

*greater the hydrogen ion concentration=lower the pH

*lower the hydrogen ion concentration=higher the pH

*pH of 7=neutral (pure water)

*pH below 7=acid

*pH above 7=base

*body fluids and blood has pH range of 7.3-7.5

*pH changes can alter the funtion of molecules

-buffer systems: help control the body's acid-base balance suitable for life

-substances that keep the pH ranges from fluctuating

-most body fluids are buffered

-if a person's pH falls below 7, they could die or go into a come

CHNOPS

carbon

hydrogen

nitrogen

oxygen

phosphorus

sulfur

for every number difference you multiply by 10

pH 5 is 100 times more acidic than pH 7 (2 away=10X10)

pH 4 is 10,000 times more acidic than pH 7 (3 away=10X10X10)

-contain carbon and hydrogen atoms

-carbon forms covalent bonds with atoms

-other carbons

-hydrogen

-nitrogen

-oxygen

-carbons in the organic molecules can form a long hydrocarbon chain or ring structure

structure: R--OH

compound: alcohol as in ethanol

significance: polar, forms hydrogen bond, present in sugars and some amino acids

*think hydroxy cut (sugar cut)

structure: R---C

compound: carboxylic acid as in acetic acid

significance: Polar, acidic, present in fatty acids and amino acids proteins

*COOH think Coors beer

structure: R---N

compound: amine as in tryptophan

significance: polar, basic, forms hydrogen bonds, present in amino acids. proteins

NH2

structure: R---O--P--OH

compound: Organic phosphate as in phosphorylated molecules

significance: polar, acidic, present in nucleotides and phospholipids

*in some amino acids

PH2O4

1. monomer: a building block or subunit

2. polymer: a large organic molecule made from monomers

*dehydration synthesis or condensation reaction: reactions that produce a polymer

*hydrolysis reaction: reactions that split a polymer

two or more monomers join chemically to form a polymer and water.

glucose+fructose---->sucrose+water

*water always appears on the right side of the arrow and it is a product

-digestion of food

-the splitting of polymers with water producing monomers

water+sucrose---->glucose+fructose

*water is always on the left side of the arrow and it serves as the reactant

category              example             subunit(s)

carbohydrates       polysaccharide    monosaccharide

lipids                    fat                    glycerol and fatty acids

proteins               polypeptide         amino acids

nucleic acids        DNA, RNA            nucleotide

needed for a source of energy(obtained from breads, pastas, fruits, and rooted vegetables)

consists of several subclasses:

1. the monosaccharides (e.g. glucose)

2. the dissaccharides (e.g. sucrose)

3. the polysaccharides (e.g. starch)

*the monosaccharides and dissaccharides (the sugars) provide an immediate energy source for organisms

*some polysaccharides store energy (i.e. starch)

*other polysaccharides contribute structurally (i.e. cellulose)

subclass of carbohydrate: simple sugars with a backbone of 3 to 7 carbon atoms

*ready energy for organisms

*glucose and fructose: 6 carbon sugars (hexoses) and arranged in ring structures 

-isomers of one another

-each have the formula C6H1206 but they differ in arrangement of the atoms

-glucose-->found in blood of animals (source of biochemical energy--ATP--in nearly all organisms)

*ribose and deoxyribose: 5 carbon sugars (pentoses)

-contribute to the backbone of DNA and RNA

subclass of carbohydrates

consists of two simple sugars

-contain two monosaccharides joined by a dehydration reaction

-maltose: two glucose molecules

-sucrose: (table sugar) glucose + fructose

-lactose: galactose + glucose (in milk)

-nonpolar polymer molecules that do not dissolve in water

-composed of the monomers fatty acids and glycerol

*glycerol: a water-soluble compound with three hydroxyl groups

-fats function as long-term stored  energy sources

-cellular membranes, including the plasma membrane, are a bilayer of phospholipid molecules

-certain hormones are derived from cholesterol, a complex ring compound

(1) fats and oils (triglycerides)

(2) phospholipids

(3) waxes

(4) steroids

-make up adipose or fat tissue

*purpose of adipose tissue is to insulate (heat) and act as a cushion around the organs

*phospholipids: type of lipid found as the main component of cell membranes

-resemble a fat molecule except for phosphate group attached to fatty acids

*waxes:type of lipids have long chains of fatty acids with alcohol functionalgroups attached and carbon ring formations

-water-proofing substance; protect & lubricate hair and skin

*steroids (sterols): type of lipids with carbon rings but NO fatty acid chains (ex. cholesterol- found in cell membrane)

-cholesterol used to make vitamin D, bile salts in liver, aid in fat digestion, hormones: testosterone and estrogen

1. carbohydrates

2. lipids

3. proteins

4. nucleic acids

-subclass of carbohydrates

-energy storage molecules

-consists of many simple sugars bonded together by dehydration synthesis reaction

-polymers of monosaccharides

-not soluble in water and do not pass through the plasma membrane of the cell

*starch: (vegetables) straight chain of glucose molecules

*two forms found in plants (1) amylose and (2) amylopectin

*glycogen: highly branched polymer of glucose with many side branches

*storage form of glucose (sugar) in animals

*cellulose: cell wall of plants (ex. cotton)

*indigestible by humans due to unique bond between glucose molecules

*digested by grazing animals

*most abundant organic molecule on Earth

*chitin: polymer of glucose with an amino group attached to each glucose.

*exoskeleton of insects and anthropods

-composed of 3 fatty acids and glycerol

*glycerol: a water soluble compound with three hydroxyl groups

-biological function: long term energy storage

-neutral fats (do not react with other molecules)

-2 types of fatty acids

unsaturated: have one or more double bonds between the carbons

*oils contain unsaturated fatty acids and are liquid at room temperature

saturated: have single bonds between the carbons

*fats contain saturated fatty acids and are solid at room temp

-stored triglycerides in animals make up adipose or fat tissue

*purpose of adipose tissue is to insulate (heat) and act as a cushion around organs.

**ex. butter, lard, and vegetable oils

-glycerol, 2 fatty acids, and phosphate group

-found as the main component of cell membranes

-resemble a fat molecule except for phosphate group attached to fatty acids

-when placed in water, the polar heads face outward and the nonpolar tails face each other.

-^property makes them suitable molecules to form the plasma membrane of cells.

(lipid)

-long chain of fatty acid & alcohol functional groups attached and carbon ring formations.

-cuticle on surface of plants that prevents water loss

-protect and lubricate hair & skin

(sterols)

-type of lipid with carbon rings but no fatty acid chains

-each steroid differs from other steroids by the functional group attached to the carbon skeleton.

*have skeletons of four fused carbon rings and vary according to attached functional groups; these functional groups determine the biological functions of various steroid molecules

*examples: cholesterol, testosterone, and estrogen

a component of an animal cell's plasma membrane, and is the precursor of the steroid hormone (aldosterone, testosterone, estrogen, calcitriol, etc)

*a diet high in saturated fats and cholesterol can lead to circulatory diseases

-many and varied functions:

*support (ex. keratin & collagen fibers)

*enzymes: proteins that act as catalysts to accelerate chemical reactions within a cell

*transport (channel and carrier proteins in the plasma membrane, and hemoglobin that transports oxygen and rbcs

*defense (antibodies that prevent infection

*hormones are regulatory proteins that influence the metabolism of cells

*motion within cells and by muscle contraction is provided by the proteins myosin and actin

-composed of amino acids (aka monomers)

-structure of amino acids contains two functional groups: amino group NH3 and carboxyl group COOH (acidic)

-20 different amino acids recognized by cells (that make proteins)

-R groups differ, ranging from single hydrogen to complicated ring compounds

-a peptide bond is a covalent bond between 2 amino acids (atoms of a peptide bonds share electrons unevenly--- oxygen is more electronegative than nitrogen)

-peptide: two ore more amino acids bonded together

*Polypeptide: chains of many amino acids joined by peptide bonds

protein that bind up oxygen so that it can be transported within the body
-quaternary structure

-the protein of red blood cells

-4 polypeptide chains called globin

-heme group (each chain has one....it has an iron atom in center)

oxygen atoms attracted to the iron atoms in heme groups

-abnormal hemoglobin: Sickle-Cell Anemia

*genetic disorder

*persons rbcs are sickled (abnormal) in shape

*amino acid giutamate is replaced with valine producing mutation

*not enough oxygen carried in blood

*organ damage results & cardiovascular system is damaged

-each protein has levels of structure resulting in a particular shape

-hydrogen, ionic, and covalent bonding, plus hydrophobic interactions, all help maintain a protein's normal shape

1. primary structure: the protein's own particular sequence of amino acids (polypeptide chain)

ex. insoline (lower sugar levels)

2. secondary structure: results when a polypeptide coils or folds in a particular way; characterized by two shapes:

-(alpha) helix

-(beta) sheet 

ex. keratin

3. tertiary structure: results when proteins are folded (folding and twisting of polypeptide), giving rise to the final three-dimensional shape

ex. myoglobin (protein of muscle)

4. quaternary structure: results when two or more polypeptides are combined

ex. Hemoglobin is globular protein with quaternary structure of 4 polypeptides

-protein shape changes

-protein does not function properly

-factors changing shape:

*pH changes

*temperature (hot or cold)

-proteins are synthesized, chaperone proteins help them fold into their normal shape (also may correct misfolding)

-certain diseases, such as Creutzfeldt-Jakob disease, is likely due to misfolded proteins: called prions

-genes are composed of DNA (deoxyribonucleic acid).

*DNA specifies the correct ordering of amino acids in proteins, with RNA as a messenger

-polymers of nucleotides:

DNA: nucleic acid has 2 strands and twists into a helix

RNA: (ribonucleic acid) has strands straight or coiled

nucleotide: composed of (1) sugar (ribose-RNA, or deoxyriboxe-DNA), (2) one phosphate group, and (3) one nitrogen base (adenine, guanine, thymine, cytosine, or uracil)

*the nucleotide ATP (adenosine triphosphate) serves as a carrier of chemical energy in cells (contains three phosphate groups, ribose sugar, and adenine base)

*ATP is a high-energy molecule because the last two phosphate bonds release energy when broken

*energy released from ATP breakdown is used in the energy-requiring processes of the cell, such as synthetic reactions, muscle contraction, and the transmission of nerve impulses.

*in cells, the terminal phosphate bond is hydrolyzed, leaving ADP (adosine diphosphate); energy is released when this occurs

SUGAR: deoxyribose

BASES: adenine, thymine, cytosine, guanine (ATCG)

STRANDS (HOW MANY?): double stranded

HELIX (YES OR NO): yes

SUGAR: ribose

BASES: adenine, uracil, cytosine, guanine (AUCG)

STRANDS (HOW MANY?): single stranded

HELIX (YES OR NO): no

-nucleotides that are vitamins

-needed for enzyme function

-major kind NAD & FAD

occurs when two strands of DNA are held together by hydrogen bonds between purine and pyrimidine bases

*the # of purine bases always = # of pyrimidine bases

*In DNA, thyamine is always paired with adenine and cytosine is always paired with guanine.

-so in DNA, A + G = C + T