Biology Unit 5: Protein Synthesis

What are the 3 types of RNA?

1. Messenger RNA (mRNA) 2. Ribosomal RNA (rRNA) 3. Transfer RNA (tRNA)

What are the 4 differences between DNA and RNA?

1. The sugar is ribose in RNA, not deoxyribose. 2. Uracil replaces thymine in RNA as a base and pairs with adenine. 3. RNA is a single strand, not double. 4. RNA is found IN AND OUT OF NUCLEUS.

Not all genes are active at the same time! Name 3 examples that correspond with the terms below: 1. Rarely Expressed 2. Constantly Expressed 3. Cyclical

1. adrenaline 2. hair growth 3. estrogen (periods)

what are the steps for translation? (specific)

1. mRNA leaves nucleus and binds to ribosome 2. tRNA with anticodon UAC and amino acid Methionine binds to start codon 3. next tRNA comes to ribosome 4. Enzyme joins 2 A.A. -- creating peptide bond 5. 1st tRNA leaves 6. 2nd tRNA slides over bringing mRNA and AA chain along 7. next codon in ribosome is ready for tRNA anticodon (process continues until stop codon) 8. when protein is complete, ribosome complex falls apart, releasing new protein.

RNA has 2 different jobs (don't list the types of RNA) ... what are they?

1. messenger between DNA and ribosomes 2. carries out the process by which proteins are made from amino acids

DNA Review: 1. Where is the DNA found? 2. What does DNA code for?

1. nucleus ONLY 2. genes that make proteins

What is protien synthesis?

A 2 stage process where DNA is used to produce proteins which code for traits -- aka gene expression

What are anticodons?

A set of three nucleotides bases found on the tRNA. It is complementary to the codons on the mRNA.

What is gene expression?

When the product of a gene (specific protein) is being ACTIVELY PRODUCED by a cell.

Protein Review: Fill in the blank -- Proteins are made up by __________ ________. Different proteins are made up by _______________ _____________ of _________ _________.

amino acids; different combinations; amino acids

T/F: introns leave the nucleus

False, they do not leave the nucleus; they may be old DNA no longer used which regulate gene expression

What does RNA polymerase do?

binds to DNA, unzips it, and uses one strand of DNA as template to BUILD A SINGLE STRANDED mRNA

What does mRNA do?

copies code from DNA in nucleus and takes code to ribosome factory

Translation purpose:

decodes mRNA into proteins tRNA carries amino acids to the ribosome and decodes mRNA 3 bases @ a time amino acids are joined together to make proteins

What are genes?

directions for building all proteins needed by organism.

DNA review: Fill in the blanks -- DNA is a _________ helix, and its monomer is a ___________. It has 3 parts, ________ _________, ____________ ____________, and a _________ ________.

double; nucleotide; DEOXYribose sugar; nitrogenous bases; phosphate group.

Fill in the blank -- Before mRNA leaves the nucleus ____________ are cut out so just the code for ___________ ____________________ is left. THEN, ___________ are spliced together to form final mRNA that leaves the nucleus.

introns; protein production; exons

Fill in the blank -- Chromosomes are divided into segments called _______________.

genes

What are introns?

non-coding segments or DNA -- Removed (inTRons = TRash)

AFTER TRANSCRIPTION: Fill in the blank -- mRNA leaves __________ and goes to _____________ so _______________ can occur.

nucleus; ribosome; translation

Fill in the blank -- Before mRNA passes out of the nucleus to enter the cytoplasm, it is ______________/____________ because we need to __________ the non-______________ segments of DNA

processed/edited; remove; non-coding

Why do we need transcription?

~DNA has a code for protein that needs to be made ~Proteins are made in the ribosomes ~DNA is too large to leave the nucleus (double stranded) ~RNA can leave the nucleus (Single Stranded)

Define Translation:

tRNA decodes message from mRNA by carrying amino acids to make a protein at the ribosome.

What does tRNA do?

transfers or carries one amino acid to the ribosome to match up with mRNA and build a protein.

What are the 3 stop codons?

UAG, UAA, UGA

what is the **start** codon and what does it code for?

AUG -- Methionine

What does cell differentiation mean?

All your cells have different functions.

Why is it important for gene expression to be regulated?

Cell would produce many molecules that it does **not** need. It would be a waste of energy and raw materials. ~~ Different kinds of cells require different kinds of molecules to function

Why isn't the DNA found anywhere else?

It is too big to leave the nucleus.

How does the DNA get to a ribosome so proteins can be made? (basic answer)

RNA helps us get from DNA to protein in ribosomes

Fill in the blank -- RNA has ______ instead of Thymine

Uracil (U)

What are the two phases in protein synthesis (name them)?

Transcription and Translation

Define Transcription:

Transferring DNA to mRNA so it can leave the nucleus and travel to the ribosome.

what is a codon?

a series of 3 mRNA bases that code for specific amino acid

What does rRNA do?

along with proteins, makes up ribosomes and is responsible for correctly matching amino acids with mRNA codon

What are exons?

code for amino acids, joined together (EXons = EXpressed)

what are the steps for translation? (Basic)

mRNA (carrying DNA instructions) and tRNA (carrying amino acids) meet in ribosome where rRNA help match them up. Amino Acids join together to make a protein/ polypeptide.