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cell theory

idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells

nucleus

the center of an atom which contains the protons and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities

Eukaryote

organism whose cells contain nuclei

prokaryote

unicellular organism lacking a nucleus

organelle

specialized structure that performs important cellular functions within a eukaryotic cell

cytoplasm

material inside the cell membrane- not including the nucleus

nuclear envelope

later of two membranes that surrounds the nucleus of a cell

chromatin

granular material visible within the nucleus; consists of DNA tightly coiled around proteins

chromosome

threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next

nucleolus

small, dense region within most nuclei in which the assembly of proteins begins

ribosome

small particle in the cell on which proteins are assembled; made of RNA and proteins

endoplasmic reticulum

internal membrane system in dells which lipid components of the cell membrane are assembled and some proteins are modified

golgi apparatus

stock of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

vacuole

cell organelle that stores materials such as water, salts, proteins, and carbohydrates

mitochondrion

cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use

chloroplast

organelle found in dells of plants and some other organisms that captures the energy from the sunlight and converts it into chemical energy

cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

centriole

one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope

cell membrane

thin, flexible barrier around a cell; regulates what enters adn leaves the cell

cell wall

strong supporting layer around the cell membrane in plants, algae, and some bacteria

lipid bilayer

double-layered sheet that forms the core of nearly all cell membranes

concentration

the mass of solute in a given volume of solution, or mass/volume

diffusion

process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated

equililbrium

when the concentration of a solute is the same throughout a solution

osmosis

diffusion of water through a selectivity permeable membrane

isotonic

when the concentration of two solutions is the same

hypotonic

when comparing two solutions, the solution with the lesser concentration of solutes

hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

facilitated diffusion

movement of specific molecules across cell membranes through protein channels

active transport

energy-requiring process that moves material across a cell membrane against a concentration difference

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

phagocytosis

process in which extensions of cytoplasm surround and engulf the large particles and take them into the cell

pinocytosis

process by which a cell takes in a liquid from the surrounding environment

exocytosis

process by which a cell releases large amounts of material

cell specialization

the process in which cells develop in different ways to perform different tasks

cell division

process by which a cell divides into two new daughter cells

mitosis

part of eukaryotic cell division during which the cell nucleus divides

cytokinesis

division of the cytoplasm during cell division

chromatid

one of two identical "sister" parts of a duplicated chromosome

centromere

are where the chromatids of a chromosome are attached

interphase

period of the cell cycle between cell divisions

cell cycle

series of events that cells go through as they grow and divide

prophase

first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus

spindle

fanlike microtubule structure that helps separate the chromosomes during mitosis

metaphase

second phase of mitosis, during which the chromosomes line up across the center of the cell

anaphase

the third phase of mitosis, during which the chromosomes pairs separate and move toward opposite poles

telophase

fourth and final phase of mitosis, during which the chromosomes begin to disperse into a tangle of dense material

cyclin

one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

cancer

disorder in which some of the body's own cells lose the ability to control growth

transformation

process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria

bacteriophage

virus that infects bacteria

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

base pairing

principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

chromatin

granular material visible within the nucleus; consists of DNA tightly coiled around proteins

histone

protein molecule around which DNA is tightly coiled in chromatin

replication

copying process by which a cell duplicates its DNA

DNA polymerase

enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule

the cell theory states:

1. all living things are composed of cells. 2. cells are the basic units of structure and function in living things. 3. new cells are produced from existing cells.

prokaryotic cells

have genetic material that is not contained in a nucleus

eukaryotic cells

contain a nucleus in which their genetic material is separated from the rest of the cell

proteins

assembled on ribosomes

endoplamic reticulum

the site where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell

golgi apparatus

modify, sort, and package proteins and other materials from the endoplasmic reticulum for storage in the cell or secretion outside the cell

mitochondria

organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use

chloroplasts

organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynethesis

cytoskeleton

a network of protein filaments that helps the cell to maintain its shape. it is also involved in movement.

cell membrane

regulates what enters and leaves the cell and also provides strength and protection

cell wall

provide support and protection for the cell

osmosis

the diffusion of water through a selectively permeable membrane

cell cycle

a cell grows, prepares for division, and divides to form two daughter cells, each which then begins the cycle again

4 phases of mitosis

prophase, metaphase, anaphase, telophase

cyclins

regulate the timing of the cell cycle in eukaryotic cells

Avery

discovered that the nucleic acid DNA stores and transmits the genetic information from one generation of an organism to the next

Hershey and Chase

concluded that the genetic material of the bacteriophage was DNA, not protein.

Watson and Crick

made a model of DNA was a double helix, in which two strands were wound around each other

DNA replication

the DNA molecule separates into two strands, then produces two new complementary strands following the rules of base pairing. Each strand of the double helix of DNA serves as a template, or model, for the new strand.

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