DNA and Protein Synthesis Notes August 28, 2019

I. Nucleic Acid Review

Name of the molecule identified by the arrow: Phosphate group Nitrogen base Adenine Sugar 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Name given to the circled structure: Nucleic acid Amino acid Nucleotide Nucleus 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

The type of reaction responsible for joining molecules A and B Hydrolysis Dehydration A B 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Let’s assume the following strand of DNA contains the information needed to make a protein. This segment of DNA is known as a____: Nucleotide Codon Translation Gene mRNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Which is single stranded? DNA RNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

The two strands of DNA are bonded together in the middle by their… Sugars Phosphates Nitrogen bases 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Which one contains nitrogenous bases A, T, G and C? DNA RNA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

I. Protein Synthesis It’s a process DNA -> RNA -> Amino Acids (Protein)

Three processes in this unit… Replication (DNA DNA) Transcription (DNA mRNA) Translation (RNA Protein)

A. DNA Replication Occurs in the nucleus prior to any cell division Enzyme is used to “unzip” or “unwind” the DNA

DNA Replication (cont.) Another enzyme is used to build a complementary strand of DNA from the template piece of original DNA Nitrogenous bases pair up A – T C - G As a result, you create two identical strands of DNA

Let’s Practice ATC GGC TAT TAG CCG ATA Replicate the following strand of DNA using the correct nitrogenous bases: ATC GGC TAT TAG CCG ATA

B. Transcription DNA strand unzips The bonds between the nitrogen bases are broken Initiated by an enzyme that binds to a site on DNA A single strand of mRNA (messenger RNA) is made Pair up the bases A  U T  A C  G G  C mRNA then travels from nucleus to cytoplasm

Transcription

Where in the cell does transcription take place? Cytoplasm Mitochondria Nucleus Golgi Body Vacuole 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Any given segment of DNA has directions that make unique what? Glucose Proteins Lipids Blood cells 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

If a DNA strand has the following sequence of base pairs – A C T G G T C C A A , then the mRNA strand would have what sequence? T G A C C A G G T T A C T G G T C C A A T G U C C U G G T T U G A C C A G G U U 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

a. Why is mRNA called messenger RNA? Because it carries the directions to make a protein to the ribosome like a message

4. Types of RNA mRNA- messenger Brings message from nucleus to ribosomes in cytoplasm rRNA- ribosomal Make up a ribosome tRNA- transfer “transfers” amino acids from the cytoplasm to the ribosome to be added to the chain

The difference between RNA and DNA is what? The phosphates The sugars The nitrogen bases The way the monomer units bond 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

mRNA is synthesized in the nucleus and travels to the cytoplasm to meet up with which organelle? Mitochondria Ribosome Golgi Body Lysosome Nucleus 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

C. Translation mRNA meets up with a ribosome…why?? Function of ribosome is to be site for protein synthesis tRNA molecules bring amino acids to ribosomes A mRNA codon will pair with a tRNA anticodon Codon: 3 Nitrogen base sequence in mRNA that specifies a specific amino acid Anticodon: 3 Nitrogen base sequence in tRNA

Translation (cont.) As tRNA’s are added, amino acids are bonded together and will be released as a fully functional protein

How do you know what amino acids make up a particular protein? We use an mRNA codon chart

Mitochondria Nucleus Ribosomes Cytoplasm Where in the cell does transcription, the first part of protein synthesis, take place? Mitochondria Nucleus Ribosomes Cytoplasm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

DNA has the directions to make what? Glucose Nucleotides Proteins Monosaccharides 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

After a strand of mRNA is made where does it go? Ribosome Mitochondria Lysosome Vacuole 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Mitochondria Nucleus Golgi body Cytoplasm Where in the cell does translation, the second part of protein synthesis, take place? Mitochondria Nucleus Golgi body Cytoplasm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Molecules called tRNA’s are floating around the cytoplasm carrying what? mRNA’s Glucose DNA Nucleotides Amino Acids 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

An mRNA codon is made up of how many nitrogen bases? 1 3 6 24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Using your mRNA codon chart, what amino acid would a ribosome call for if the codon was A A C ? Phenylalanine Glutamine Asparagine Lysine Tyrosine 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

What protein would be synthesized from the following mRNA strand What protein would be synthesized from the following mRNA strand? A C U U U C G A A U A C Threonine – phenylalanine – glutamate – tyrosine Phenylalanine – leucine – methionine – valine Tyrosine – glutamate – phenylalanine – threonine Lysine – cysteine – arginine – histidine 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

What protein would be synthesized from the following DNA segment What protein would be synthesized from the following DNA segment? T A A G T A C G C T A G Isoleucine – alanine – histidine – alanine Isoleucine – histidine – alanine – isoleucine Phenylalanine – leucine – valine – arginine Isoleucine – leucine – threonine – lysine 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

How would you assess your comprehension of DNA & Protein Synthesis? B C D 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17