Bio Unit 3 Module 6

DNA

Shaped like a double helix, and made of nucleotides. They hold the code that produces different proteins, which determine traits.

Nitrogen bases

In DNA, a pair of these make the "rung" or "step" of the double helix. They are also used by RNA. In DNA there are four bases used Adenine, Thymine, Guanine and Cytosine represented by the letters A,T,G,C. In RNA Uracil replaces Thymine so their letters become A,U,G,C.

Nucleotide

An individual unit that form nucleic acids in DNA. These are made up of deoxyribose, a phosphate and a base of Adenine, Cytosine, Guanine, or Thymine.

RNA

A single strand of nucleotides. Three important types of RNA are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). mRNA is used during transcription, and all three types of RNA are used during translation.

Messenger RNA (mRNA)

It is a type of RNA. It copies a portion of the DNA code during transcription and carries it outside the nucleus to help create a protein during translation.

Ribosomal RNA (rRNA)

It is a molecular component of a ribosome, that produces protein. It works together with messenger RNA (mRNA) and transfer RNA (tRNA) during translation to form the string of amino acids that make up a protein.

Transfer RNA (tRNA)

It is a type of RNA that carries amino acids to the ribosome to form a protein during translation.

Codon

Made of three nitrogen bases on a strand of DNA or RNA. Controls the placement of one amino acid, which helps to determine the final protein produced.

Mutation

A change in the original DNA sequence which may lead to a change in the protein produced.

DNA replication

Occuring during the interphase of the cell cycle, before the cell divides Forming one "old" strand and one "new" strand. During this process hydrogen bonds are broken, nitrogen bases are formed using enzymes, and strands are unzipped.

protein synthesis

This process makes protein. Every hereditary trait is controlled by proteins. This process follows the DNA as it is copied by messenger RNA (mRNA) during transcription, to transfer RNA (tRNA) as is carries amino acid during translation, through the production of protein by the ribosome.

heredity

The passing of a traits from one generation to the next.

double helix

The ladder-like shape of DNA.

complementary base pairing

The nitrogen base that make up DNA pairs two molecules together, Adenine to Thymine, or A-T, and Guanine to Cytosine, or G-C. So a strand labelled CGAT could be paired with a strand labelled GCTA.

gene

A section of DNA which is used as a code for the production of a protein.

transcription

When messenger RNA (mRNA) copies the DNA to carry instructions outside of the cell. mRNA follows complementary base pairing of the DNA (A-T, G-C), except uses Uracil instead of Thyme, so if the DNA strand was CTA, the paired mRNA strand would be GAU.

translation

uses the messenger RNA (mRNA) to build a protein. The amino acid from transcription is carried to the mRNA by the transfer RNA (tRNA), then the ribosome will release them them in a string of amino acids that form the protein.

tRNA anticodon

Three nitrogen bases at the bottom of the transfer RNA (tRNA) that pair with a codon on the messenger RNA (mRNA). This allows for the amino acid the tRNA carries to be passed along. The complementary base pairing of the tRNA and mRNA is A-U, G-C.

point mutation (substitution)

When one nitrogen base is substituted for a different base during DNA replication. For example A is replaced by C. This may change the single amino acid produced which may change the final protein produced. Sickle Cell anemia, where the blood cells are misshapen is an example of this.

Frameshift mutation

As DNA and messenger RNA (mRNA) are read in groups of three nitrogen bases called codons, if there a nitrogen base is added or deleted to the codon this can change the final protein produced and lead to disease.

Smaller surface area means

Larger volume ratio

Larger surface area means

Smaller volume ratio

Why do cells divide?

Maintain a workable volume and to make more cells

Why is prokaryotic cell division simpler than eukaryotic cell division?

They don’t have a nucleus or membrane bound organelles

Chromatin

Interphase DNA, “stringy” form

Chromatid

Copy of DNA

Chromosome

Make up a nucleus

Interphase

Normal life of the cell

Mitosis

Divides the nucleus in eukaryotic cells.

Prophase

The first phase where membrane is broken down

Metaphase

The second phase where chromosomes are moved into the middle of the cell

Anaphase

The third phase where spindle fibers shorten

Telophase

The fourth phase where spindle fibers are broken down

Cytokinesis

Separation of the cytoplasm

Cancer is caused by

Uncontrolled cell division

Binary Fission

Unicellular organism divides into 2

Budding

Simple organisms produce much smaller than those of the parent organism

Sporulation

An organism produces spores-tiny packets of DNA used for reproduction

Vegetative propagation

A portion of a plant goes through cell division to produce another plant

Regeneration

Part of an animal goes through cell division to produce a new organism

Gametes

Sex cells, such as sperm and egg

What are the four nitrogen bases?

Adenine, thymine, guanine, and cytosine

In RNA, adenine pairs with uracil but

Thymine pairs with Adenine

mRNA

Copies the DNA when the DNA unzips a gene

Peptide bond

Amino acids are bonded together in order to form a polypeptide

What makes DNA unique?

The sequence

DNA replication is…

Semi-conservative