Biology Regents Review

DNA

Genetic material with instructions for building proteins

DNA structure

two single strands of DNA that twist and form a double helix. Each strand is formed from a series of nucleotides.

Nucleotide

the DNA building block that consists of a sugar, phosphate, and base.

DNA replication

Process that results in two identical copies of DNA

DNA Replication Base pairing rule

A pairs with ?

G pairs with?

A pairs with T

G pairs with C

RNA

A single stranded polymer that is produced by DNA. There are three types: mRNA, tRNA, and rRNA

Protein synthesis

The process that creates proteins from a sequence of DNA made up of chains of amino acids. This process occurs in the ribosome and involves two main stages: transcription (copying DNA into mRNA and translation (reading mRNA to build the protein).

Where is DNA found

in the nucleus

Transcription changes….

DNA to mRNA

Transcription is

The first step of protein synthesis. The DNA code is copied into

messenger RNA (mRNA). The DNA double helix unwinds, and an

enzyme called RNA polymerase reads one strand of DNA and

creates a complementary mRNA strand.

Base pairing rule Transcription (DNA-mRNA)

A pairs with ?

G pairs with ?

A pairs with U

G pairs with C

Translation goes from

mRNA to a Proteins

Translation is

The second step of protein synthesis. mRNA travels to the ribosome, the cell's protein-making

factory. Here, the mRNA sequence is read in sets of three bases (codons), each specifying a

particular amino acid. Transfer RNA (tRNA) brings the appropriate amino acids to the ribosome to form a protein.

The Codon Chart is used to

Determine which amino acids will be assembled

Gene expression

An organism’s environment can affect the expression of some genes.

Type of Protein

Enzymes:

A type of Protein that acts as biological catalysts to speed up chemical reactions. Enzymes are catalysts used in digestion and synthesis.

Enzyme reaction rates are affected by:

Shape- Lock and Key Model, if it is the wrong shape, it will not work.

Temperature- each Enzyme works best at a specific temperature.

pH- each Enzyme works best at a specific pH.

Structural Proteins:

Provide shape and support to cells and tissues.

Cell receptors:

Proteins on cell surfaces that receive and transmit signals.

Hormones:

Chemical messengers that control/ regulate many bodily functions (ex: insulin)

Antibodies:

Immune system proteins that identify and kill foreign substances.

Smallest to biggest of the structures

(smallest) Cells- Tissues- Organs- Organ Systems- Organism (biggest)

Organelles

Small parts that make up a cell ( each has at least one specific function)

cell membrane

1. Separates the internal environment of the cell from the outside environment.

2. Controls material transport into and out of the cell (selective permeability)

3. Cellular communication: Recognizes and responds to chemical signals by using receptor molecules.

4. A

Nucleus

Control Center of the cell and contains DNA (the program or code of life)

1. B

Mitochondria

SIte of cellular respiration in both plant and animal cells.

1. C

Cell Wall

provides shape and structure in plant cells only

1. D

Vacuoles

Store waste and water (large in plant cells, small in animal cells)

1. E