Protein Synthesis: Making Protein

Name: ______Date: ______Block: _____

PROTEIN SYNTHESIS: MAKING PROTEIN

 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 2

 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

 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. 3

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. 4

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) 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

 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 5

 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. 6

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. 7

 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.

 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. 8

 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 9

 Dominant trait – an allele that is fully expressed in heterozygotes; represented by a capital letter

 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: 10

Pedigree: 11

Incomplete Dominance Crosses:

Codominance Crosses:

Multiple Allele Crosses: 12

BLOOD ANTIGENS ANTI- RECEIVE DONATE GENOTYPES TYPES (MARKERS) BODIES FROM? TO? (FIGHTERS)

TYPE A

TYPE B Blood TYPE AB Type:

TYPE O 13

Blood Type Crosses:

Sex-linked Crosses: