37 terms

Chapter 4: Cell Organelles, DNA, Protein Synthesis and Mutations.

STUDY
PLAY

Terms in this set (...)

chromosome
A long strand of chromatin that is tightly coiled around proteins and condensed into a compact rod- shaped or X-shaped structure.
DNA
A double helix molecule called Deoxyribonucleic Acid. It is made up of building blocks called nucleotides. DNA is found in the nucleus.
nucleus
An organelle that controls all of the cell activities. It is surrounded by a membrane.
nucleolus
Organelle in the nucleus that makes ribosomes.
cell membrane
A thin covering of the cell that controls what comes in and out of the cell. It also separates the inside of the cell from its external environment. Found in both plant and animal cells.
cell wall
Found in plant cells. It is a tough, rigid structure that supports and protects the cell.
cytoplasm
A jelly-like substance that contains the organelles as well as water and sugar.
organelle
A part of the cell that has a particular function to do for the cell.
mitochondria
An organelle that is specialized to provide energy for cells by changing glucose into energy.
chloroplast
Found in plant cells. An organelle that traps light energy from the Sun to make food such as glucose for the plant.
ribosome
A small organelle that makes proteins. It can be free floating or attached to the rough endoplasmic reticulum.
protein
An essential molecule required for cells to function. Can be enzymes or hormones.
endoplasmic reticulum (ER)
A network of membrane-covered channels in a cell that transport materials made in the cell such as proteins.
vesicle
A membrane-covered sac made by the endoplasmic reticulum and Golgi body. It transports substances such as proteins to the Golgi body and the cell membrane.
vacuole
Membrane-covered storage containers in cells. Plants have a large central vacuole for the storage of water and starch.
Golgi body
An organelle that processes, sorts and packages proteins for transport.
nuclear membrane
Separates and protects the DNA and contents of the nucleus from the cytoplasm.
nuclear pores
Holes in the nuclear membrane that allows certain molecules to enter and leave the nucleus.
lysosome
An organelle filled with enzymes / chemicals that break down old organelles and cells when they no longer function. (Janitor to keep cell clean)
chromatin
DNA loosely wound around proteins. This is how DNA exists most of the time.
gene
A small section of DNA located at specific places on a chromosome. Genes contain information that codes for a particular trait or protein.
enzymes
Special proteins that speed up chemical reactions that occur in each cell - ex.) digestive enzymes.
hormones
A special protein that acts as a chemical messenger to other cells of the body.
protein synthesis
The making of proteins needed by the cells and body to function. Steps: DNA instructions are copied by RNA. RNA leaves through nuclear pores and takes instructions to ribosome in cytoplasm or ER. Protein made by ribosome is taken to Golgi by vesicle to be repackaged before another vesicle takes it to the cell membrane where protein can be released from the cell.
RNA
A single stranded molecule called ribonucleic acid that is involved in protein synthesis.
mutation
A permanent change in the DNA sequence.
gene mutation
A change in the specific order of one of the A,T, G and C bases that make up a gene. There are 3 types: substitution, addition and deletion.
positive mutation
A mutation that benefits an individual and increases the chance of survival. Example: having a protein that prevents HIV from infecting a person's cells.
negative mutation
A mutation that is harmful to an individual and decreased the chance of survival. Example: having a genetic disease such as sickle cell anemia or cystic fibrosis.
neutral mutation
A mutation that does not affect the organism or its chance of survival. Example: different hair colour such as the Spirit Bear.
mutagens
A substance that increases the chance of a mutation occurring or causes a mutation. Example: viruses, radiation for UV rays or X-rays, cigarette smoke, pollutants or household chemicals.
carcinogens
Mutagens that lead to cancer.
gene therapy
Used to treat mutated genes by replacing the bad copy of the gene with the good copy.
nucleotide
The building block of DNA made up of 3 parts: deoxyribose sugar group, phosphate group and one of 4 nitrogen bases (adenine, thymine, guanine or cytosine).
substitution mutation
One base is changed for another base. Not necessarily serious.
addition mutation
One base is added to a gene. Serious.
deletion mutation
One base is removed from a gene. Serious.