ATI Teas 7 Science Study Guide (Nurse Cheung)

changes between states of matter

condensation = gas to liquid; molecules of the gas slow down and become closer together

evaporation = liquid to gas; molecules of the liquid gain enough energy to break away from the surface of the liquid

sublimation = solid to gas; molecules of the solid gain enough energy to break away from the surface of the solid

deposition = gas to solid; molecules of the gas slow down and become closer together

melting = solid to liquid; molecules of the solid gain enough energy to break away from each other.

freezing = liquid to solid; molecules of the liquid lose enough energy to stay together

empirical evidence

information that is gathered through observation and experimentation

qualitative evidence

described in terms of quality or characteristics

quantitative evidence

described in terms of quantity or amount

reliable evidence

information that can be trusted and is consistent

valid evidence

information that accurately represents what it is supposed to represent

placebo

harmless substance that has no therapeutic effect

independent variable

variable that is being tested and is not affected by other variables

controlled variable

variable that is not being tested and is held constant

scientific method

First, identify a problem or question.

Second, gather information about the problem or question.

Third, form a hypothesis, which is a possible answer to the problem or question.

Fourth, design and conduct an experiment to test the hypothesis.

Fifth, analyze the data from the experiment and draw conclusions.

Sixth, communicate the results of the experiment.

proton

particle with a single positive charge

neutron

neutron is a particle with no electric charge

electron

particle with a single negative charge

isotopes

atoms of the same element that have a different number of neutrons

atomic mass

atom is the total number of protons and neutrons; Carbon-12 (number of 6 protons + the number of 6 neutrons)

atomic number

number of protons in an atom

atoms charge

more electrons than protons = negative charge

more protons than electrons = positive charge

protons and electrons are equal = neutral

ions

atoms that have gained or lost protons, and as a result, have a charge either positive or negative

cations

atoms that have lost one or more electrons; positively charged ions

anions

atoms that have gained one or more electrons; negatively charged ions

periodic table

columns = groups

rows = periods

orbitals

s = 2

p = 6

d = 10

f = 14

ionic bonds

atoms trade electrons in order to achieve stability

covalent bonds

atoms share electrons in order to achieve stability

electronegativity

matter

anything that has mass and occupies space

physical properties

different properties of a substance that can change their state without changing the identity of the substance

states of physical properties

mass = amount of matter in an object; grams (g)

volume = amount of space an object occupies; liters (L)

density = mass of an object divided by its volume; grams per liter (g/L)

phases of a substance

temperature = measure of the average kinetic energy of the molecules in a substance; higher temperature = more energy and more space they take up

pressure = measure of the force exerted on an object by the surrounding atmosphere; higher pressure = molecules are forced together

states of matter

solid = definite shape and volume; molecules packed together in a tight pattern

liquids = definite volume but take the shape of their container; molecules are not packed together as tightly

gases = no definite shape or volume; molecules are far apart from each other

plasma = state of matter found in the stars; electrons have been stripped from the atoms

valence electrons

outermost energy level of an atom

reactants

substances involved in the reaction

products

new substances formed by the reaction

combustion reaction

type of reaction that happens when a substance reacts with oxygen (O) to form carbon dioxide (CO) and water (H)

coefficient

number that is placed in front of a symbol or formula in order to multiply it

mole

unit of measurement of amount of a substance

catalysts

speeds up the reaction; lower the activation energy by providing an alternative pathway for the reaction to occur

endothermic reactions

absorb heat

exothermic reactions

release heat

dynamic equilibrium

forward and reverse reactions are occurring at the same time

static equilibrium

concentrations of the reactants and products are not changing

activation energy

minimum amount of energy that is needed for a chemical reaction to occur

cohesion

similar molecule surrounding and binding to another molecule; water with water

adhesion

dissimilar molecules binding to another molecule; water with glass

solvent

substance that dissolves in another substance

solute

substance that dissolves in a solvent

hydrophilic

attracts water molecules

hydrophobic

repels water molecules

solubility

ability of a solute to dissolve in a solvent

concentration of a solution

amount of solute that is dissolved in a given amount of solvent

dilution

adding solvent to a solution to decrease the concentration of the solution

molarity

unit of measurement that describes the concentration of a solute in a solution;

mole of solute/liters of solution (mol/L)

osmosis

water molecules moving from an area of high water concentration to an area of low water concentration through a semi-permeable membrane

hypertonic

net flow of water out of cell

hypotonic

net flow of water into cell

semi-permeable membrane

barrier that allows some molecules to pass through but not others

diffusion

molecules moving from an area of high concentration to an area of low concentration

passive transport

process of molecules moving that do not require energy, only require that the molecules be in motion

active transport

process of molecules moving that requires energy (moving against the concentration gradient), from an area of low concentration to an area of high concentration

excessive hydrogen ions

CO2 + H2O ↔ H2CO3

HCO3− + H+ ↔ H2CO3

acid

molecule that increases the concentration of hydrogen ions in a solution; pH = 0-6.9

base

molecule that decreases the concentration of hydrogen ions in a solution; pH = 7.1-14

neutral

pH = 7

buffer

resists change in pH

neutralization reactions

chemical reaction between an acid and a base

chemicals

help build cells

macromolecules

chemicals that are essential to life; carbohydrates, proteins, lipids, and nucleic acids

cell

basic unit of life; all living things are made up of cells

tissues (4 types and functions)

made up of cells that have a similar structure and function;

types = epithelial, connective, muscle, nervous

functions = protection, support, movement, communication

organs

made up of tissues that work together to carry out a specific function

organ systems (11 systems)

group of organs that work together to carry out a specific function;

integumentary

skeletal

muscular

nervous

endocrine

cardiovascular

lymphatic

respiratory

digestive

urinary

reproductive

organisms

made up of one or more organ systems

cell is composed of 10 parts:

cell membrane

cytoplasm

Golgi Apparatus

lysosome

mitochondrion

nucleus, ribosomes

rough endoplasmic reticulum

smooth endoplasmic reticulum

vacuole

cell membrane

layer of protein and fat that surrounds the cell;

selectively permeable

cytoplasm

jelly-like substance that contains the cell's organelles;

supports and suspends the structures inside the cell membrane;

transfers material required for other cellular processes

Golgi apparatus

organelle that helps to package and transport molecules within the cell;

helps process proteins and lipid molecules

lysosomes

organelles that contain enzymes that break down food and other molecules;

aid in digestion and recycle old cell materials;

destroy invading bacteria and viruses

mitochondria

organelles that produce energy for the cell;

convert nutrients into ATP (cell's energy source)

nucleus

organelle that contains the cell's hereditary information

deoxyribonucleic acid (DNA)

responsible for the cell's growth, reproduction, and function;

genes that are coded with instructions to produce proteins in the cell;

made up of two long chains of nucleotides that twist to create a double helix

ribosomes

organelles that help synthesize proteins = essential for the cell to carry out its functions;

round on either the rough-endoplasmic reticulum or floating in the cytoplasm

rough endoplasmic reticulum (RER)

organelle that helps to package and transport molecules within the cell;

involved in the synthesis of proteins

smooth endoplasmic reticulum (SER)

organelle that helps to package and transport molecules specifically lipids within the cell but does not contain ribosomes;

involved in carbohydrate metabolism and inactivates toxins along with harmful metabolic products

vacuole

organelle that stores food, water, and other materials;

helps to maintain the cell's shape

mitosis

process of cell division that results in two genetically identical daughter cells.

mitosis (4 cell cycle stages)

interphase

prophase

metaphase

anaphase

telophase

interphase (mitosis)

first stage of the cell cycle;

cell grows and carries out its normal functions;

DNA starts to replicate

prophase (mitosis)

second stage of the cell cycle;

chromosomes condense and become visible;

nuclear envelope breaks down

metaphase (mitosis)

third stage of the cell cycle;

chromosomes line up in the middle of the cell

anaphase (mitosis)

fourth stage of the cell cycle;

chromosomes are pulled apart to opposite sides of the cell;

cell division begins

telophase (mitosis)

fifth and final stage of the cell cycle;

new nuclear envelope forms around the chromosomes;

chromosomes uncoil and become less visible;

cell divides into two daughter cells

meiosis

cell division that results in four genetically diverse daughter cells

meiosis (2 main stages)

meiosis I:

interphase

prophase I

metaphase I

anaphase I

telophase I

meiosis II:

prophase II

metaphase II

anaphase II

telophase II

meiosis I:

interphase

prophase I

metaphase I

anaphase I

telophase I

Interphase = first stage of meiosis; cell grows and carries out its normal functions; DNA starts to replicate.

Prophase I = second stage of meiosis; homologous chromosomes pair and start to crossover.

Metaphase I = third stage of meiosis; homologous chromosomes line up in the middle of the cell in pairs

Anaphase I = fourth stage of meiosis; one chromosome from each homologous pair is pulled apart to opposite sides of the cell

Telophase I = fifth stage of meiosis; two daughter cells start to form, each cell has half the number of chromosomes as the original cell (mixture of genetic information)

meiosis II:

prophase II

metaphase II

anaphase II

telophase II

Prophase II = sixth stage of meiosis; daughter cells contain half of the chromosomes from the original cells

Metaphase II = seventh stage of meiosis; chromosomes line up in the middle of the cell again

Anaphase II = eighth stage of meiosis; sister chromatids are pulled apart to opposite sides of the cell

Telophase II = ninth and final stage of meiosis; cells divide into four genetically diverse daughter cells (haploids)

chromosomes

long, thread-like structures found in the nucleus of cells made up of DNA and histone proteins; winding structure condenses DNA and allows regulation

prokaryote = one chromosome

eukaryote = multiple chromosomes

genes

basic unit of heredity; made up of DNA and are responsible for the characteristics of an organism; passed down from parent to offspring

structural genes

responsible for the physical traits of an organism

regulatory genes

control the activity of other genes

complementary bases

hydrogen bonds pair up to hold the two strands of DNA together;

G to C and T to A (DNA);

G to C and U to A (RNA)