How can we help?

You can also find more resources in our Help Center.

77 terms

Exam 1 Biology

STUDY
PLAY
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.