* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download II - Humble ISD
Gene regulatory network wikipedia , lookup
Cell-penetrating peptide wikipedia , lookup
Promoter (genetics) wikipedia , lookup
Peptide synthesis wikipedia , lookup
Protein adsorption wikipedia , lookup
Eukaryotic transcription wikipedia , lookup
RNA silencing wikipedia , lookup
Non-coding DNA wikipedia , lookup
Protein (nutrient) wikipedia , lookup
Polyadenylation wikipedia , lookup
RNA polymerase II holoenzyme wikipedia , lookup
List of types of proteins wikipedia , lookup
Bottromycin wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Protein structure prediction wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Amino acid synthesis wikipedia , lookup
Messenger RNA wikipedia , lookup
Biochemistry wikipedia , lookup
Molecular evolution wikipedia , lookup
Non-coding RNA wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Gene expression wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Expanded genetic code wikipedia , lookup
Name _________________________________________________________ Test Date ______________ UNIT 9 – PROTEIN SYNTHESIS I. THE IMPORTANCE OF RNA (pp. 300-301) The instructions in ________ are carried out through the making of _____________. Protein synthesis occurs at the ___________________ in the ____________________ of the cell, but DNA is found in the ___________________. DNA cannot leave the nucleus because __________________________________, so another molecule is required to take the genetic code from the nucleus to the _________________ so protein synthesis can take place. This molecule is __________________________________ or ________. A. RNA Structure – RNA differs from DNA in three ways: Characteristic Sugar Base Structure DNA RNA RNA is able to leave the nucleus through the _________________________ because it is a _________________________________; thus, the genetic code can be carried out. B. Types of RNA – There are three principal forms of RNA involved in carrying out the genetic instructions of DNA: 1. mRNA - _________________ RNA. Carries instructions (_________________) from DNA in _______________ to __________________. “___________________” for genetic code. 2. tRNA - __________________ RNA. Carries (transfers) _________________________ to ribosome according to instructions encoded in ____________. 3. rRNA - ________________ RNA. Structural component of ____________________; also produces _____________________ to bond _________________________________ together to form __________________. II. PROTEIN SYNTHESIS (pp. 301-306) Protein synthesis takes place in two steps: A. Transcription The word “transcribe” means to ____________________. Transcription creates a _________________ copy of DNA’s instructions that can be carried out to the ___________________. Transcription takes place in the ________________. B. Translation Translates or ____________________ the _____________________ sequence of ___RNA to an ___________________________ sequence to make a protein. Translation takes place at the ___________________. III. A CLOSER LOOK AT TRANSCRIPTION, THE FIRST STEP IN PROTEIN SYNTHESIS A. First, the enzyme ___________________________, unzips part of the DNA molecule. B. RNA nucleotides are moved in according to base pairing rules and __________ is synthesized. There are 2 important ways that transcription differs from replication: 1. Only _____________________ of the DNA molecule is copied in transcription. 2. In RNA, the nucleotide that pairs with adenine is ________________. The nitrogen base, ____________________, is not found in RNA. C. When the mRNA is first transcribed, there are long sequences of __________________ that are not required for the synthesis of the protein called _______________. The DNA sequences that code for the protein are known as ______________. Introns are edited out (cut out) of the mRNA before it leaves the nucleus and the remaining __________ are spliced together to form the final mRNA. D. mRNA leaves the ________________ through the ___________________________ and travels to the ______________________, the site of protein synthesis. For the following “gene”, give the corresponding mRNA sequence: TACCCGGAATTCGAG ___________________________________________________________________ IV. A CLOSER LOOK AT TRANSLATION, THE SECOND STEP IN PROTEIN SYNTHESIS A. Codons – A Way to “Read” mRNA The __________________ (building blocks) of proteins are ____________________. There are ______ amino acids used to build the proteins essential for life. The mRNA message is read by the ribosome in groups of three _____________________ called _______________. Each codon codes for a specific amino acid. A codon can be made up of any combination of the 4 nucleotides; in other words, there are 4 X 4 X 4, or ______ possibilities for codons. Since there are only 20 amino acids, many different codons represent the same amino acid. There are codons that are start (______) and stop signals for the amino acid chain. The genetic code is _________________; that is, the same __________ codes for the same _________________ in all organisms. CODON CHART For the following codons, give the name of the corresponding amino acid: a. UAC - ___________________________________ b. GCA - __________________________________ c. AGA - __________________________________ d. CCU - __________________________________ For the following amino acids, give all the possible codons: a. arginine - _____________________________________________________________________ b. glycine - ______________________________________________________________________ B. tRNA The function of tRNA is to transfer the _____________________ specified by the __________________ to the ____________________ for protein synthesis. The _______________ of the cell is stocked with all 20 amino acids required for protein synthesis. The tRNA molecule carries an ________________ at one end and at the other end, it has a group of _____ nucleotides known as an ________________. The anticodon binds to the mRNA codon cording to base pairing rules and insures that the proper amino acid is brought to the ribosome. C. Building a Protein The ___________ slides through the ribosome a ____________ at a time. As the codon is read, the tRNA with the corresponding _______________________ comes to the ribosome carrying its amino acid. The next mRNA codon is read, and another __________ arrives with its amino acid, according to its anticodon and base-pairing rules. As another tRNA arrives at the ribosome, the first tRNA is bumped off, but it leaves its amino acid behind. This process continues and a chain of amino acids forms until a stop codon is reached. Then the ribosome releases the amino acid chain, which coils & folds to form a _______________. V. GENETIC MUTATIONS (pp. 307-308) A mutation is a ________________________________________________________________ Although many mutations are harmful, some mutations are ______________, and others may be very _____________________ to an organism. There are two categories of mutations: A. Chromosomal Mutations A chromosomal mutation involves a change in the _______________ of the entire chromosome or a change in the total _____________ of chromosomes. Does not alter individual _____________. These errors generally occur during __________________ or __________________. B. Types of Chromosomal Mutations C. Gene Mutations A gene mutation is a change in one gene on an individual chromosome. This may result in a change in only one ___________________ or many nucleotides making up that gene might be altered. The incidence of gene mutations is relatively low due to the action of ___________________ that ________________________ the DNA sequence after ______________________________.There are two types of gene mutations: 1. Point Mutations – This is a change in one or just a few ________________, but the total number of nucleotides in the gene is not changed. This might have no effect, or change one amino acid. Therefore, the resulting ________________ may or may not be altered. 2. Frameshift Mutations – This involves the _________________ or _________________ of a _______________________. When a nucleotide is inserted or deleted, this shifts the reading of the remainder of the _____________; therefore, the ___________________ of the remainder of the mRNA is altered. This will usually result in tremendous changes in the ________________________ chain and completed protein. Suggested Study Questions p. 315 (3-10, 12-16, 18-21, 23)