Download 1 Name: Date: Block: _____ PROTEIN SYNTHESIS: MAKING

Name: __________________________________________ Date: ________________ Block: _____
PROTEIN SYNTHESIS: MAKING PROTEIN
RNA
 Made up of
 Phosphate
 Ribose (a sugar)
 Four bases
 RNA bases are:
 Adenine
 Guanine
 Cytosine
 _______________________ (instead of thymine)
 Single stranded
 Forms part of ribosomes
 Two types of RNA:
 _________(transfer)
 mRNA (messenger)
TRANSCRIPTION: USING DNA TO MAKE mRNA
 _______________________ (an enzyme) unzips DNA by breaking the Hydrogen bonds
between the bases.
 Only one strand of DNA is transcribed.
 Complementary RNA nucleotides are added to the DNA strand.
 DNA RNA
 A–U
 G–C
 T–A
 C–G
 The start codon is the signal for the place to start transcription.
 Transcription stops at the __________ codons.
 The sequence of bases along DNA that is transcribed is a gene.
 The RNA that is made is mRNA.
mRNA PROCESSING
 After mRNA is made, enzymes may cut out pieces of the strand.
 The sections that are removed are called __________________.
 The sections that remain are called ___________________ and are put together.
 The finished/mature mRNA strand then leaves the nucleus and is ready for translation.
THE IMPORTANCE OF PROTEINS
 Each gene controls the making of a protein.
 A gene is section of DNA that gives instructions for a specific protein to be made
 20 amino acids make up all proteins
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Proteins are required for almost every reaction that occurs in your body!
CODONS
 Codon - _________________ bases in a row that determine the amino acid that is used to make
a protein.
 Some codons do not represent amino acids, but instead act as stop signals (the end of a protein).
 Note, one amino acid may have more than one codon.
TRANSLATION: FROM mRNA TO PROTEIN
 Begins when a ribosome attaches to an mRNA strand.
 mRNA is used to make a specific protein (or polypeptide).
RIBOSOMES
 The organelle where proteins are made.
 They are made up of 2 subunits with 2 binding sites.
tRNA
 tRNA (transfer RNA) is a strand of nucleotides that has an ___________________attached to it.
 tRNA carries the appropriate amino acid to the mRNA/ribosome complex.
 If mRNA is UGG then the tRNA is _______.
 Translation begins with the start codon.
 Each amino acid that is brought in to the ribosome is attached to the growing amino acid chain (or
protein)
 The bond between amino acids is called a ___________________ bond.
 About 15 amino acids are added per second.
 Translation stops when a stop codon is reached.
 There are no tRNA’s for the stop codons.
 The protein is released to do its job.
WHERE DOES THE PROTEIN GO?
 Sometimes the finished protein goes into the rough ER. The rough ER transports it to various
places including the plasma membrane, ________________ apparatus, and cytoplasm.
 The Golgi processes and packages proteins. Fro example, some proteins have sugars attached
to them. The remodeled proteins leave the Golgi in ____________________ (sacs) to go to other
parts of the cell or to leave the cell.
BIOTECHNOLOGY: The future is here!
MUTATIONS
 Mutation - changes in the DNA sequence that affect genetic information
 Types of mutations:
 Gene mutations - changes within a _______________ gene
 Chromosomal mutations - changes within a whole ____________________ (affects multiple
genes)
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GENE MUTATIONS
 Point Mutation - a change in a single ______________________example: changing an A to a C)
 Frame-shift Mutation - an insertion or deletion of a nucleotide that causes a different reading of
codons from the point of the change to the end of the gene
 Point Mutations
Normal
AAT TAA TAG GAT TTT AAA
Mutation
AAT TAG TAG GAT TTT AAA
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Frame-Shift Mutations
 Usually occurs as a result of an insertion or deletion
Normal
TAC GCA TGG ATT
Insertion
TAT CGC ATG GAT T
 Example using words:
THE FAT CAT ATE THE RAT
THE FAT C AT A TE T HE R AT
TEF ATC ATA TET HER AT
 Just like this mutated sentence does not make sense, frameshift mutations
make nonsense proteins that cannot do their jobs correctly.
CHROMOSOMAL MUTATIONS
 Deletion – when part or all of a chromosome is lost
 Duplication – when part of a chromosome is mistakenly _______________________
 Inversion – when part of a chromosome becomes oriented in ______________ of its normal
direction
 Translocation – when one part of a chromosome breaks off and attaches to another
nonhomologous (not the partner) chromosome
WHEN DO MUTATIONS OCCUR?
 During DNA replication, mistakes can be made when DNA polymerase adds complementary
nucleotides.
 If this mutation or mistake happens very early on in a baby’s development, the mutation can affect
the entire baby. The rest of the cells will have that same mutation.
 Remember, we all start off as one cell that must make many news cells through mitosis. Every
time your cells divide, DNA has to copy itself and mistakes can be made.
 If a one of your skin cells divides right now and a mutation occurs, this is probably not a problem.
 However, if the mutation causes certain genes to change, the new, mutated skin cell can become
a cancer cell.
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CAUSE OF MUTATIONS
 Mutagen – any agent that causes DNA to ______________________
 UV light
 Radiation
 Smoking
 Many different chemicals
GENE REGULATION
 Only ______________ of your genes are being expressed (used to make protein) at any given
time.
 Your body needs mechanisms to “turn on” or “turn off” genes.
 Chemicals can act as blocks or starters.
 Some cancers are caused by genes being turned on that should not have been! For example,
these genes can be turned on by smoking, which mutates DNA.
GENETIC ENGINEERING: Manipulating DNA
Electrophoresis
 DNA is cut by _______________________________to
make fragments.
 Restriction enzymes cut DNA at specific sequences.
 Electrophoresis is a technique that separates DNA fragments
(using electricity) in a jello-like slab based on the size of the
fragments.
 Smaller fragments are able to travel longer distances more
_____________.
 DNA has a negative charge so the fragments will flow toward
the positive electrode (opposites attract).
 If you were to compare two samples of the same DNA using
the same restriction enzymes, the banding pattern would be
the same.
 Different people make different banding patterns.
AND WHY WOULD WE DO THIS?
DNA Fingerprinting
 _______________________ Tests
 Children have a banding that is a combination of their mom’s and dad’s banding.
 Crime solving
 Identify the person who committed a crime (no two people have the same DNA)
 Medical diagnosis
 Determine if you have the gene that causes a disease or disorder.
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GMOs
 Genetically modified organism (GMO) – an organism with DNA that has been altered through
genetic engineering
 Transgenic - a GMO that has been altered with DNA from another ______________________
Transgenic Bacteria
 Bacteria have had many different genes put into them
 Some examples of human genes that are put into bacteria
 __________________ gene
 Human growth hormone gene
 Clotting factors gene
Transgenic Animals
 Used to study genes and improve the food supply
 Mice with human-like immune system genes.
 Livestock with extra copies of growth hormone genes.
 Sheep and pigs that produce human proteins in their milk.
Transgenic Plants
 Used for food supply and medical supplies
 Rice with _______________________ (beta-carotene) gene
 Genes for herbicide and pesticide resistance in plants
Cloning
 Producing genetically identical organisms from one original cell.
 We have successfully cloned pigs, cows, mice, sheep, and monkeys.
 The first animal cloned was a sheep named Dolly in 1997.
GENETICS
 Genetics – the study of _______________________ or passing on of genes
 Gene – a sections of DNA that codes for a ______________ to be made
 Allele – the _________ that a gene takes (ex. dominant or recessive)
 Homozygous – having the ____________ alleles for a trait
 Heterozygous – having __________________alleles for a trait
 Dominant trait – an allele that is fully expressed in heterozygotes; represented by a capital
letter
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Recessive trait – an allele that is not observed in heterozygotes; represented by a lower case
letter
Genotype – the _______________________ of alleles (letters) that an organism has
Phenotype – the physical trait or visible characteristic determined by the genes
GENETIC PROBLEMS
Link between meiosis and genetics:
Single Trait Crosses:
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Pedigree:
Incomplete Dominance Crosses:
Codominance Crosses:
Multiple Allele Crosses:
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Blood Type:
BLOOD
TYPES
GENOTYPES
TYPE A
TYPE B
TYPE AB
TYPE O
Blood Type Crosses:
Sex-linked Crosses:
ANTIGENS
(MARKERS)
ANTIBODIES
(FIGHTERS)
RECEIVE
FROM?
DONATE
TO?