Biology: Chapters 9-11 Review

Polypeptide

A chain of amino acids.

Mutagen

A chemical or physical agent that causes a change in a gene.

Operon

A cluster of genes in prokaryotes.

Mutation

A heritable change in genetic information.

Any change in DNA base sequence is called?

A mutation.

An operon is regulated by

A repressor

Anticodon

A sequence of three bases on a tRNA molecule that is complementary to a sequence of bases on an mRNA molecule.

What does DNA do?

DNA contains all biological information needed by the cell.

What are mutagens?

Environmental factors that cause mutations.

____ are spliced together in forming messenger RNA

Exons

Cell differentiation in eukaryotes in controlled by

Gene Regulation

Polyploidy

Having an extra set of chromosomes.

Master control genes, called ____ genes, regulate organs that develop in specific parts of the body.

Homeotic

Gene expression

How genetic information is put into action in a living cell.

Protein function is governed by what?

Its shape.

______ carries copies of the instructions for making proteins from DNA to other parts of the cell.

Messenger RNA

Four different consequences of mutation?

Neutral: no advantage or disadvantage Deleterious: lead to difficulty for organism Lethal: causes organism to die Advantageous: creates benefit for organism

A region of DNA where a repressor can bind is a

Operator

A group of genes that are regulated together is called an

Operon

The region of DNA where the production of an RNA strand begins is called the

Promoter

DNA holds the biological information of the cell, while _____ define the structure and function of a cell.

Proteins.

_____ contains sugar ribose

RNA

An operon is regulated by a repressor that binds to the operator region downstream of the promoter where

RNA polymerase binds. The repressor prevents transcription when it is bound to the operator site. The repressor is removed by a small molecule that signals the need for genes to be transcribed.

The enzyme that assembles a complementary strand of RNA on a DNA template is called

RNA polymerase.

Which enzyme is necessary for transcription?

RNA polymerase. It beings to a promoter region of the DNA to initiate transcription.

What is central dogma?

The central dogma of molecular biology states that DNA is transcribed into RNA, which is translated into proteins.

Translation

The decoding of an mRNA message into a protein.

Where does transcription take place?

The nucleus of eukaryotic cells, and the mRNA is then transported to the cytoplasm.

What is translation?

The process in which mRNA molecules direct the synthesis or proteins.

Why do skin cells differ from muscle cells in humans?

The proteins produced in a cell definite the structure and function of that cell. The presence or absence of proteins has a large impact on the functions going on in the cell and so genes are regulated. Although DNA has the codes for a wide range of proteins, only certain sets of proteins are made at any given time. In the case of multicellular organisms, this fact allows the cells to conserve resources and direct to their own fates to become specialized.

Genetic code

The sequence of "bases" that serves as the "language" of life.

Codon

The three consecutive bases that specify a single amino acid to be added to the polypeptide chain.

The process of ____ produces a complementary strand of RNA on a DNA template.

Transcription

What two mobile chemical messengers regulate gene expression?

Transcription factors and miRNA (RNA interference)

DNA is copied through a process called what?

Transcription.

_____ transfers amino acids to ribosomes.

Transfer RNA

Is gene expression regulated? If so, what does that mean?

Yes; this means not all genes are expressed at the same times in an organism.

What are the four important key points of DNA?

a. Every cell contains a complete copy of every gene needed by the organism throughout its life. b. DNA is kept in the nucleus of eukaryotic organisms. c. DNA is a double-stranded molecule composed of deoxyribose, phosphate, and the nitrogenous bases thymine, adenine, guanine, and cytosine. d. Biological information is encoded in the sequence of bases in DNA.

What are the key concepts of translation?

a. Ribosomal RNA (rRNA) and proteins combine to form the ribosome complex. This complex is present in the cytoplasm. b. During translation, an mRNA molecule docks onto the ribosome. Two transfer RNA (tRNA) molecules bring the first two amino acids corresponding to the first two triplets of bases in the mRNA into the ribosome. The amino acids are bonded together through a dehydration synthesis reaction. This process is repeated as the ribosome moves down the mRNA molecule. c. The triplet of bases on an mRNA corresponding to an amino acid is called a codon. The complementary triplet of bases on a tRNA molecule carrying that amino acid is called an anticodon.

What are the four key points of transcription?

a. The copy is messenger RNA (mRNA), which has a complementary sequence to the DNA sequence that it was transcribed from. b. mRNA is a single-stranded molecule composed of ribose, phosphate, and the nitrogenous bases uracil, adenine, guanine, and cytosine. c. RNA polymerase is the enzyme necessary for transcription. It binds to a promoter region of the DNA to initiate transcription. d. Transcription takes place in the nucleus of eukaryotic cells, and the mRNA is then transported to the cytoplasm. Some mRNAs are edited to remove non-coding regions called introns. The remaining exons (coding regions) are spliced together to form a mature mRNA that leaves the cell nucleus.

What is mRNA?

mRNA is a single-stranded molecule composed of ribose, phosphate, and the nitrogenous bases uracil, adenine, guanine, and cytosine.

What are the five types of mutation?

point mutations: base substitution frameshift mutations: change the reading frame insertion deletion translocation