Question

genetic code study guide

1. what are the 4 nitrogenous bases for dna?
2. what are the 4 nitrogenous bases for rna?
3. compare and contrast the structural differences of dna and rna.
4. what does semiconservative mean?
5. what would a semiconservative dna structure look like?
6. what kinds of bonds are holding the nitrogenous bases together?
7. what is chargaffs rule for dna and rna?
8. what is the process of synthesis, modification, and transportation of proteins?
9. what are the different enzymes involved in protein synthesis? what are their functions?
10. what are the functions of the different types of rna?
11. what occurs during translation?
12. what happens during transcription?
13. list and describe the different mutations.
14. what is the relationship between the nucleus and the ribosomes?
15. what would be an example of a dna sequence that is identical during replication and transcription?
16. where can mutation errors occur?
17. how are disorders expressed in humans?
18. what would be affected if a dna molecule did not properly replicate?
19. what would happen if all the enzymes involved in dna replication stopped working properly?
20. what does the process of gene regulation impact?
21. what kind of mutation causes sickle - cell anemia and how is it expressed in humans?

Explanation:

1. The four nitrogenous bases for DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
2. The four nitrogenous bases for RNA are adenine (A), uracil (U), guanine (G), and cytosine (C).
3. DNA is usually double - stranded, has deoxyribose sugar, and thymine. RNA is usually single - stranded, has ribose sugar, and uracil instead of thymine.
4. Semiconservative means that during DNA replication, each new DNA molecule consists of one old strand and one new strand.
5. A semiconservative DNA structure would have one parental strand and one newly synthesized strand in each of the two daughter DNA molecules.
6. Hydrogen bonds hold the nitrogenous bases together.
7. Chargaff's Rule for DNA states that the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine. RNA is usually single - stranded and doesn't strictly follow this rule in the same way.
8. The process of synthesis, modification, and transportation of proteins involves transcription (DNA to RNA in the nucleus), translation (RNA to protein at the ribosome), and post - translational modifications.
9. Enzymes in protein synthesis include RNA polymerase (synthesizes RNA from DNA template), aminoacyl - tRNA synthetase (attaches amino acids to tRNA), and peptidyl transferase (forms peptide bonds between amino acids).
10. mRNA (messenger RNA) carries the genetic code from DNA to the ribosome, tRNA (transfer RNA) brings amino acids to the ribosome, and rRNA (ribosomal RNA) is a component of the ribosome.
11. During translation, the ribosome reads the mRNA codons and tRNA brings the corresponding amino acids to form a polypeptide chain.
12. During transcription, RNA polymerase uses a DNA strand as a template to synthesize a complementary RNA molecule.
13. Mutations include point mutations (substitution of a single nucleotide), insertions (addition of nucleotides), and deletions (removal of nucleotides).
14. The nucleus contains DNA which is transcribed into RNA. The RNA then travels to the ribosomes in the cytoplasm where proteins are synthesized.
15. A non - coding DNA sequence like a regulatory region might be identical during replication and transcription as it doesn't code for proteins directly but is important for gene regulation.
16. Mutation errors can occur during DNA replication, exposure to mutagens (chemicals, radiation), or errors in DNA repair mechanisms.
17. Disorders in humans can be expressed through mutations in genes that affect protein function, leading to abnormal physiological processes.
18. If a DNA molecule did not properly replicate, daughter cells may receive incorrect genetic information, leading to potential cell death, abnormal cell function, or genetic disorders.
19. If all the enzymes involved in DNA replication stopped working properly, DNA replication would halt, cells would not be able to divide properly, and eventually, the organism may die due to lack of cell replacement and growth.
20. Gene regulation impacts when, where, and how much a gene is expressed, which affects the development, function, and differentiation of cells.
21. Sickle Cell Anemia is caused by a point mutation in the beta - globin gene. This mutation causes the production of abnormal hemoglobin, which makes red blood cells sickle - shaped, leading to anemia, pain, and organ damage.

Answer:

1. Adenine (A), Thymine (T), Guanine (G), Cytosine (C)
2. Adenine (A), Uracil (U), Guanine (G), Cytosine (C)
3. DNA: double - stranded, deoxyribose, thymine; RNA: single - stranded, ribose, uracil
4. Each new DNA has one old and one new strand
5. One parental and one new strand per daughter DNA
6. Hydrogen bonds
7. DNA: A=T, G = C; RNA: not strictly same rule
8. Transcription, translation, post - translational mods
9. RNA polymerase (synthesizes RNA), aminoacyl - tRNA synthetase (attaches amino acids), peptidyl transferase (forms peptide bonds)
10. mRNA (carries code), tRNA (brings amino acids), rRNA (component of ribosome)
11. Ribosome reads mRNA, tRNA brings amino acids for polypeptide formation
12. RNA polymerase makes RNA from DNA template
13. Point (nucleotide substitution), insertion (nucleotide addition), deletion (nucleotide removal)
14. Nucleus has DNA for transcription, ribosomes use RNA for protein synthesis
15. Non - coding regulatory region
16. During replication, exposure to mutagens, DNA repair errors
17. Through mutations affecting protein function
18. Incorrect genetic info, cell death/abnormal function
19. Replication halts, cell division issues, organism death
20. When, where, and how much a gene is expressed
21. Point mutation in beta - globin gene; abnormal hemoglobin, sickle - shaped RBCs, anemia etc.