the use of energy to move materials from a region where they are in a lower concentration to a region where they are in a higher concentration.
adenosine triphosphate (ATP)
a compound that stores energy.
molecules that are the building blocks of proteins.
a change in the way cells are able to control their own reproduction.
the basic units (or building blocks) of life. They form the tissues, organs, and systems of the human body.
(or plasma membrane) a membrane that surrounds the contents of the cell and separates it from other cells and the environment.
a theory that states that cells are the units of life and all cells come from preexisting cells.
a process in which glucose is broken down through a series of reactions to produce ATP, as well as carbon dioxide and water.
large molecules in the nucleus made up of DNA and protein.
a triplet of mRNA nucleotides that directs the placement of an amino acid into a polypeptide chain.
a group of cells that support and hold things together.
a genetic disease in which the affected person receives a mutated gene from both the mother and the father and has problems with recurring lung infections because certain cells in their lungs do not function properly.
fluid within the cell membrane of a cell that contains water and other chemicals.
the random movement of molecules from a region of higher concentration to a region of lower concentration.
a cell that has two full sets of chromosomes. In humans, this is 46 chromosomes.
special enzymes that carry out the neat and orderly replication process of DNA.
two strands that twist around each other like coils. In biology, it refers to the double chain of nucleotides that form a molecule of DNA.
endoplasmic reticulum (ER)
an elaborate membrane system throughout the cytoplasm.
proteins that help chemical reactions take place. Enzymes help cells build products like proteins, make copies of DNA molecules, and carry out all their functions.
sheets of cells that form your skin, the lining of your breathing and digestive systems, and the covering of the organs of your body.
sperm in males or eggs in females.
specific regions of the DNA that code for the production of specific proteins. Genes are responsible for specific products and functions characteristic of the particular cell type.
the flattened sacs that help sort the proteins synthesized by the rough ER and ribosomes.
having one complete set of chromosomes. In humans a haploid gamete cell has one set of the 23 chromosomes.
an enzyme that helps the DNA molecule start to unwind at one end.
a special kind of cell division that produces eggs and sperm. It involves two cell divisions, but only one duplication of the genetic materials, so that each daughter cell receives only one chromosome of each chromosome pair, or one complete set of the chromosomes for that organism.
messenger ribonucleic acid (mRNA)
a type of nucleic acid that takes the code for a protein from DNA to the ribosome where the protein is produced.
cell organelles that are the factory and storage center for ATP, which is used as energy by the cell in making cellular products and carrying out the functions of the cell.
cell division in which the parent cell reproduces into two identical daughter cells as a result of division of the duplicated chromosomes and division of the cytoplasm.
groups of cells that can contract.
a permanent change in the DNA of a cell.
a group of cells that can process information and send messages or signals.
repeating molecular units that make up DNA.
an important cell organelle that is the control center of the cell, containing the chromosomes with their genetic material, DNA.
a group of tissues that work together.
the parts of the cell that are organized for specific functions, such as the nucleus.
the movement of water across a semipermeable membrane in response to a solute concentration difference.
the movement of a substance across a membrane due to a concentration difference and not requiring the expenditure of energy.
the process through which DNA is copied.
the sites for protein synthesis.
an enzyme that makes a complementary mRNA from the DNA template.
almost all the cells in your body-the cells that make up the structure of your body and all your organs, such as the brain, heart, muscles, intestine, and liver. All cells except gamete cells.
a cell that divides to renew itself and, also, can give rise to many cell types.
the blockage of, or break in, a blood vessel that serves a portion of the brain, causing the cells in that brain region to get sick and/or die.
organs that work together.
a group of similar cells working together to carry out a specific function.
the process of making a messenger RNA molecule from a segment of DNA.
transfer RNA (tRNA)
a type of RNA that brings the amino acids to the ribosomes to make proteins.
protein synthesis. The coded message in mRNA is translated to produce a protein.
abnormal tissues produced when cancer cells continue to divide.