molecules study guide

Activation energy

The amount of energy that is sufficient for a particular chemical reaction to occur

How do chemical reactions occur

When reactants collide with sufficient energy to react.

Enzymes are very specific

Each enzyme can catalyze only one chemical reaction by working on one particular reactant

What chemical reactions are enzymes involved in, necessary for organisms to live reproduce and grow

Digestion, respiration, reproduction, movement, and cell regulation

What is a catalyst

A substance that charges the rate of a chemical reaction or allows a chemical reaction to occur at a lower than normal temperature, each catalyst works best at a specific temperature and pH

When enzymes are pushed past their range, what happens?

They will become denatured or broken down

What do catalyst work by?

Lowering the activation energy of a chemical reaction

A catalyst is not what

Consumed or altered during a chemical reaction so it can be used over and over again

Catalyst are also what

Any substance that increases the rate of a chemical reaction without it being consumed or used up

Enzymes are what

Proteins that have a specific function or special job and act as catalyst

Nucleus contains what

The chromosomes which are composed of DNA, and functions in the genetic control of the cell

What are ribosomes

The sites of protein synthesis, some are located on the ER, others are found in the cytoplasm

Endoplasmic reticulum

A complex, extensive network that transports materials throughout the inside of a cell

Rough ER

Has ribosomes attached to the surface

Smooth ER

Has no ribosomes attached

What does DNA determine

The structure of the proteins essential for life function and processes

DNA is

Universal and has the same structure so it can be found modeled the same in any organism

When a particular protein is needed

The cell must make the protein through the process of transcription and translation. DNA molecules do not leave the nucleus of the cell

Where does protein synthesis occur

Ribosomes located outside of the nucleus. Therefore, the code must be carried from the nucleus to the cytoplasm

What is transcription

The process by which a portion of the molecule of DNA is copied into a complementary strand of RNA.

What is the process of transcription?

1. An enzyme attaches to the DNA molecule at the gene of interest. A start codon tells the enzyme where to begin on the strand.

2. The two strands of DNA separate at that location

3. Complementary RNA nucleotides bond to the nitrogen basis on one of the separated DNA strands

4. The chain of RNA nucleotides forms a single-stranded molecule of RNA by using the DNA strand as a template

5. When a stop codon is reached the RNA strand separates from the DNA molecule, leaves the nucleus and goes through the nuclear membrane into the cytoplasm

6. The two DNA strands rejoin

What is translation

The process by which the genetic massage carried by the mRNA is used to assemble a protein

How does mRNA work

It attaches to a ribosome, which contains proteins and ribosomal RNA, the function of ribosomes to several proteins according to the genetic massage

Each three base nucleotide sequence on the mRNA is called what

A codon. Each codon specifies particular amino acids that will be used to build the protein molecule.

How does tRNA work?

It brings amino acid to the ribosome in the order specified by the codon sequence on the mRNA. At one end of each tRNA is the anticodon, a region that consist of three nucleotide basis that are complementary to the codon of mRNA, the other end of the tRNA molecule binds to the specific amino acid that is determined by the mRNA codon.

What is the translation process?

1. The anticodon of the tRNA, with its attached amino acid, compares to the codon of the mRNA, which is attached to ribosome.

2. When a second TIA with a specific amino acid pairs to the next codon in its sequence, the attach amino acid breaks from the first tRNA and is bonded to the amino acid of the second tRNA

3. The Ribosome forms a peptide bond between the amino acids, and an amino acid chain begins to form.

4. The empty tRNA moves off and picks up another matching amino acid from the cytoplasm in the cell.

5. The sequence is repeated until the ribosome reaches a stop.

What are the types of RNA importances to the cell?

mRNA is essential to the process of transcription, tRNA is essential to the process of translation, and RRNA makes that the ribosome to in which translation takes place.

All cells contain what

DNA and genes that can code for the formation of proteins

Gene sequence

It affects protein function, and proper functioning of many proteins is necessary for the proper functioning of cells

As a result of differentiation,

Different genes are activated in different cells that share the same genetic code and complex organisms.

If any organism is alive, it has what

DNA and all DNA has the same structure so the modeled DNA could be found in any living organism.

Systems of specialized cells,

They share similar structures and functions. These are carried out by proteins.