Biology MidTerm Vocabulary

fact

objective, verifiable observation

principle

statement based on repeated experimental observations

law

broad concept or principle (explains how)

theory

explanation of an observed phenomenon (explains why)

matter

anything that has mass and/or occupies space

cell

most basic unit of life

six elements necessary for life

• carbon

• hydrogen

• nitrogen

• oxygen

• phosphorus

• sulfur

CHNOPS

polar molecule

• one side is more positive, one side is more negative than the other

• dissolves in water

nonpolar molecule

• both sides are equal, no positive or negative poles are formed

  • does not dissolve in water

hydrophilic

dissolves in water (water loving)

hydophobic

does not dissolve in water (water fearing)

macromolecules

large, organic molecules that make up all living things

monomer

small, basic, sub-units

polymer

large, more complex structures made from monomers

dehydration reaction

builds a polymer by removing a water molecule to stick monomers together

hydrolysis

breaks polymers by adding a water molecule to break bonds between the monomers

cell theory

1. all living things are made out of cells

2. cells are the most basic unit of life

3. all cells come from other cells

unicellular

composed of one singular kind of cell

mulitcellular

composed of many cells that organize into tissues, organs, organ systems

organelle

specialized structure within the cell that has a certain job to help the cell function

solute

what gets dissolved

solvent

what does the dissolving

solution

uniform mixture of two or more substances

concentration

amount of solute that dissolved in solvent

concentration gradient

difference in a concentration of a substance from one location to another

photosynthesis

process where sunlight, water, carbon dioxide are converted into chemical energy stored in glucose

reactants

ingredients in a chemical equation, on the left side

products

results in a chemical equation, on the right side

cellular respiration

process where chemical energy from food is converted to energy stored in A

chemosynthesis

process of an organism making its own food using chemicals

DNA

deoxyribonucleic acid

RNA

ribonucleic acid

antiparrallel

running in opposite directions

helicase

enzyme that unzips the DNA ino two strands

primase

enzyme that makes and adds short RNA primers to help get the next step started (like key for car ignition)

polymerase

ensyme that adds complementary polynucleotides to the exposed strands, removing the RNA primers. also proofreads strand when done

ligase

enzyme that zips up new DNA strands, sealing them with phosphodiester bonds

genetic code

code of instructions for how to make protiens

codon

a set of three nucleotides on the mRNA

anticodon

“complementary” three nucleotides on the tRNA

mRNA

messenger RNA (copies instructions in DNA and carries these to the ribosomes in the cytoplasm

tRNA

transfer RNA (binds and carries specific amino acids to the ribosome)

rRNA

ribosomal RNA (makes up the ribosome along with the protiens)

transcription

DNA to RNA

translation

RNA to Amino Acids

cell cycle

a repeated pattern of growth, DNA duplication and cell division that occurs in eukaryotic cells

chromosome

one long continuous thread of DNA that consists of thousands of genes and regulatory information (humans have 46)

gene

section of DNA that contains the instructions for making a protein

chromatid

one half of a duplicated chromosome

centromere

region of the condensed chromosomes that looks pinchedt

telomere

ends of the DNA molecule

Gap 1 Phase (G1)

cell grows and makes protiens

Synthesis Phase (S phase)

DNA replication occurs, doubling the number of chromosomes

Gap 2 Phase (G2)

more cell growth and protein synthesis

prophase of mitosis

• chromosomes condense and are visible as sister chromatids

• nuclear membrane deforms

• centrioles create spindle fibers

metaphase of mitosis

chromosomes line up in the middle of the cell and the spindle fibers connect to the centromeres of each chromatid

anaphase of mitosis

• sister chromatids separate, becoming individual chromosomes

• said chromosomes move to opposite sides of the cell

telophase

• chromosomes decondense and look like chromatin

• nuclear membrane reforms at each side of the cell

• spindle fibers deform

cytokinesis

• in plant cells: cell plate forms between two nuclei and gradually becomes a membrane

• in animal cells: forms a cleavage furrow that pinches the cell into two equal parts

apoptosis

programmed cell death

cancer

uncontrolled cell division

metastasis

spreading of disease from one organ to another

carcinogen

chemical that causes cancer by mutating DNA

somatic cell

diploid body cell

gamete

haploid sex cell

diploid cell

cell that contains two full sets of chromosomes - one from each parent (2n=46)

haploid cell

cell that contains one full set of chromosomes that is a combination of one from each parent (n=23)

autosomes

chromosome that carries traits that make you who you are

fertilization

the actual fusion of egg and sperm to form a zygote

meiosis

process of cell division to make gametes

karyotype

diagram of a set of chromosomes

ploidy

the number of sets of chromosomes in each cell

• haploid: one set of chromosomes

• diploid: two sets of chromosomes

• triploid: three sets of chromosomes

zygote

cell formed when the egg and sperm come together

nondisjunction

error during meiosis in which chromosomes don’t separate properly

• can cause genetic disorders

deletion

when part or all of a chromosome is completely removed

translocation

when part of a chromosome breaks off and attaches to a different chromosome

plasma membrane

surrounds the outside of all cells and controls what goes in and out of the cell

cytoskeleton (animal cells only)

gives the cell shape and provides structural support

cytoplasm

jelly-like substance that is mostly made of water. it holds everything in place

nucleus

• contains genetic material

• protects DNA

• controls cell activity

nucleolus

located inside the nucleus and makes ribosomal RNA (makes up ribosomes)

ribosomes

located on the rough ER and makes proteins

Rough ER

packages proteins for secretion

Smooth ER

makes lipids

golgi apparatus

sorts and ships proteins where necessary (like a mailman)

lysosomes (animal cells only)

breaks down dead things and programs cell death

vacuoles

• storage unit

• small and numerous in animal cells, one large in plant cells

centrioles (animal cells only)

helps cell divide by pulling chromosomes apart

cilia (animal and bacteria cells only)

moves fluid across cell surface

flagella (animal and bacteria cells only)

moves entire through extracellular fluid (whip-like structure)

mitochondria

• where cellular respiration happens

• breaks down chemical energy in food to release usable energy in the form of ATP

• “powerhouse of the cell”

chloroplast (plant cells only)

• where photosynthesis happens

• converts light energy from the sun into chemical energy in sugar

cell wall (plant and bacteria cells only)

protects and maintains shape of plant cells