DNA & Protein Synthesis Review Guide PDF

Hamsini Bellamkonda 2/16/25 3 DNA Structure/Replication 1. The __________________ nucleotide double is the monomer of DNA. Deoxyribonuclei...

Hamsini Bellamkonda 2/16/25 3 DNA Structure/Replication 1. The __________________ nucleotide double is the monomer of DNA. Deoxyribonucleic Acid is _________________-stranded and nucleus found in the _________________ of the cell. This is also where replication takes place.DNA is shaped like a double __________________ helix ________________ or twisted ladder. 2. What is CHARGAFF’S RULE? What nitrogen bases pair up in DNA? Chargaff's rule is that the percentage of A (Adenine) is equal to the percentage of T (thymine), and the same with C and G. 3a. If a sample of DNA contained 24% Adenine, what percent would you expect to be Thymine? 24% Adenine = 24% Thymine 3b. If a sample of DNA contained 24% Adenine, what percent would you expect to be Guanine? 24 + 24 = 48, which leaves 52 Nitrogen base pair 52 / 2 = 26 26% would be Guanine Phosphate Sugar Nucleotide 4. Label 1, 2, 3, and 4 in the diagram with the following terms: nucleotide, sugar, phosphate, nitrogen base pair 5. What type of bond holds nitrogen base pairs together? Hydrogen _________________ bonds _____________. proteins 6. Genes are sequences of DNA that contain instructions for building ________________ that give you your traits. 7. Write each of the 3 enzymes involved in DNA replication in the order they appear in the process. Then, describe what they do (their role): 1. DNA Helicase: unzips the DNA from the double helix shape into two seperate strands 2. DNA Polymerase: matches the sole nitrogen bonds together for each of the two strands 3. Ligase: seals the two strands back together into two complementary strands 8. Describe how DNA replication is a semiconservative process: DNA replication is a semiconservative process because of how when it ends, the DNA molecule has one old strand from the beginning as well as one new one. **Want some practice questions? Try this practice assessment with DNA Structure/Replication Questions (posted)  The Central Dogma: Protein Synthesis Phosphate 1.​ Label the parts of a nucleotide for RNA: Base pair Sugar 2.​ How does this nucleotide differ from that of a DNA nucleotide? The base pair Thymine for DNA is replaced with Uracil for RNA. Nucleic 3.​ What type of organic macromolecules are DNA and RNA? ____________________ acids ________________ 4.​ Compare & Contrast: Fill in the chart to determine the differences between DNA and RNA Type of Nucleic Monomer Nitrogen base Number of Function Sugar Acid Pairing rules strands Contains genetic DNA (polymer) Nucleotide A and T Deoxyribose 2 information for living C and G Nucleic Acid organisms RNA (polymer) A and U Used to build proteins Amino Acid 1 Ribose Nucleic C and G Acid 5.​ During protein synthesis, three types of RNA are used. What is the function of each type of RNA and what do they look like? Type of RNA Function Image/Structure mRNA Copies down the DNA sequence in the nucleus and made in transcription, goes to a ribosome where rRNA is “read” in translation Translates the DNA sequence that the mRNA fetched rRNA used in translation so that tRNA can transfer it Transfers the codons from the translated DNA sequence tRNA into different pairs of Amino Acids used in translation 6.​ What organelle is used in Protein Synthesis? What is the function of this organelle? Ribosomes are the organelles that are used in Protein Synthesis, and the function of them is to translate genetic information into proteins. TRANSCRIPTION: Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). This is done by the enzyme RNA polymerase. DNA stores genetic material in the nucleus of cells. When transcribing DNA into mRNA, A→ U, T→ A, and C → G. The newly formed mRNA copies of the gene then serve as blueprints for protein synthesis during the process of translation. Like DNA, mRNA is made of nucleotides that contain a sugar, phosphate, and nitrogen base. Unlike DNA, mRNA contains the nitrogen base U instead of T and is only single-stranded. 7.​ Summarize what occurs in transcription. Include the necessary molecules, enzymes and location. In transcription, the mRNA gets copied DNA genetic code from a strand with the help of the RNA polymerase enzyme. The only difference when copying the genetic code is that in place of Thymine in DNA, RNA uses Uracil (U). 8.​ Fill in the mRNA strand (bottom) based on the DNA template strand. (DNA template) U A C C A U C G A U U G G A A (mRNA transcript) TRANSLATION In protein synthesis the mRNA travels to the ribosome. The ribosome contains rRNA which reads the mRNA three nucleotides at a time (AGU-CGU-ACG). This set of three nitrogen bases is called a codon. The tRNA carries an amino acid to the ribosome based on the codon. tRNA molecules contain anticodons, which are complementary (opposite) to the codons. The amino acids bond and form a protein. Proteins are what build our traits. 9.​ Explain the process of translation. Use all of the words below Word Bank: Ribosome. Translation, tRNA, protein, mRNA, amino acid, codon, rRNA During translation, mRNA travels to the ribosome, where the rRNA reads out and "translates" the genetic code from mRNA, and sequences it into codons. Codons are three base pairs read at a time. After, the tRNA contains anticodons, as well as an amino acid that matches, and when everything pairs, it creates a protein. 10.​ Define a codon: Three nitrogenous bases formed into a group. 5 11.​How many codons make up the mRNA strand in question #8? __________ 12.​Fill in terms in the blanks to show the flow of genetic information in the cell. In question b, you will place two terms above arrows as well. a.​ (Protein, Trait, Gene) Gene ______________→ Protein Trait ______________→______________ DNA Transcription mRNA Translation b.​ (Translation, Transcription, DNA, Protein, mRNA) _______________----------------------->_______________ Protein -------------------->________________ 13.​Label each of the following in the diagram below: A- Transcription B- Translation D- DNA Strand T- Base Pair R- mRNA Y- rRNA F- tRNA M- Amino Acids N- Protein Use your mRNA codon chart in your notes, online, or the teacher copy for any questions needed: 14.​Rewrite the mRNA strand you transcribed in question 8, then translate into the resulting amino acids. UACCAUCGAUUGGAA Tyr - His - Arg - Leu - Glu 15.​How does the tRNA “know” which amino acids to bring to the ribosome? (Hint: the opposite of a codon!) The tRNA knows due to the anticodons that match with the codons of the ribosome (rRNA) 16. If a portion of a messenger RNA molecule contains the base sequence U-G-A, the corresponding transfer RNA base A-C-U sequence (anticodon) is __________. Mutations 1. What part of the nucleotide is altered when a mutation occurs? The nitrogen bases. 2. When/how can mutations occur (2 processes) a.​ Transcription b.​ Translation 3. Describe the types of gene mutations below: A.​ Substitution: When a nitrogen pair gets substituted for another nitrogen B.​ Frameshift (describe why insertions and deletions are referred to as “frameshift” mutations): Insertions and deletions are referred to as "frameshift" mutations due to how the whole frame of the sequence completely shifts with bases being added and/or removed. Define Insertion- When a nitrogen base gets added to the sequence. Define Deletion- When a nitrogen base gets removed from the sequence. 4. Describe the three types of substitution mutations. How does each affect the resulting protein? ​ the substituted A.​ Missense mutation:​When ​ ​ base​changes​ the amino ​ acid​ completely. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ B.​ Nonsense mutation: ​When ​ the substituted ​ ​ base​ causes​ translation ​ to occur ​ and ​ then stop. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C.​ Silent mutation: When the substituted base doesn't change the name of the amino acid. silent 5. Multiple codons may code for the same amino acids. This best explains ___________________ mutations where changes in nucleotide bases do not alter the protein. 6. Use TWO BOLDED TERMS above to identify the specific type of mutation to the right with the original DNA on top, and mutated DNA below in the image. Explain: This is an example of a substitution mutation, because the base pair "A" was replaced with "C". However, the effect was a silent mutation because even though the base was altered, the amino acid still had no change to it.