Chapter 10 Objective Questions
1. Describe the structure and function of DNA.
DNA structure is a nucleic acid, meaning it is made up of a chain of nucleotides. Nucleotides are made up of phosphate, deoxyribose sugar, and a nitrogen base. The shape of a DNA is a twisted double helix, with two strands. DNA has 2 nucleotide chains which are like the ladder which are held by covalent bonds which are strong. The sides of the ladder are the alternating phosphate and deoxyribose. DNA is antiparallel so sides run in opposite directions. The rungs of the ladder are the bases. The bases hold the nucleotide chains together by hydrogen bonds from complimentary pairing. The A and T pairing have 2 hydrogen bonds and the C and G pairing have 3 hydrogen bonds. A and G are purines which have two rings which C and T are pyrimidine which have one ring. The function of DNA is to store and transmit genetic information, to control the production of proteins, to make parts of a cell and to reproduce cells.
2. Explain the process of mitosis.
Mitosis occurs in 4 phases. The first phase is prophase. In prophase, the condensing chromosomes are visible under a microscope. The nuclear membrane breaks down and stores in the vesicles. Spindle fibers form microtubules in the cytoplasm. The spindle fibers attach to centromere and centriole. Polar spindles extend centriole to centriole. The centrioles move to opposite poles. The second phase is metaphase. Metaphase is when the replicated chromosomes line up in the middle or the equator. The third stage is anaphase. In anaphase the enzyme breaks down the centromere. Then the chromatids separate. The spindle fibers pull the chromatid to the polar region. This makes sure that every cell gets every chromosome. The last phase of mitosis is telophase. The nuclear membrane is reforming in telophase. Also the spindle fibers are disappearing. The chromosomes are uncoiling as well. The cleavage furrow shows the division point of the cell. Then during cytokinesis the cell divides into two. Plant cells have to form a cell plate which is cell wall material carried
Related Documents: Dna and Nucleotide Chains Essay
BSC: Exam 3 (chapters 16-20) Before lecture Questions: Q: “A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses).” A: gene Q: If one strand of a DNA molecule has the sequence of bases 5'-GATTACA-3', the other complementary strand would have the sequence 3'-CTAAGTG-5' The two strands of the double helix are complementary, each the predictable counterpart of the other Adenine (A) always pairs with Thymine (T); and Guanine…
Nucleotides – DNA and RNA are made up of nucleotides – Nucleotides are made up of 1) Pentose Sugar 2) Nitrogenous Base 3) Phosphate GROUP – The bases may be purines (2 rings; adenine and guanine) or pyrimidines (1 ring; cytosine and thymine or uracil) – Bases bond using hydrogen bonds – The sugar-phosphate backbone may be generalized by 5' (five prime) and 3' (three prime); ensures nucleotides are connected and read in the correct way DNA – Controls cellular activities; carries a genetic code – encoded…
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DNA a. Structure: Nucleotide Hydrogen Bond -Phosphate -Sugar -Nitrogen Base b. Replication: DNA copies itself exactly and occurs within the Nucleus. A mistake that occurs in called Mutation (chromosomal Mutation). (C-G) (A-T) DNA polymerase is the enzymes involved Know what each person discovered: Griffith: coined the term transforming principle-(DNA that is transferred from one individual to another in genetic transformation )…
In the next stage, elongation, an enzyme called DNA polymerase is important. The DNA polymerase attaches to each strand at the replication origins, reading the nucleotides and finding the complement base. Because the leading strand runs in the same direction that it was unzipped, the DNA polymerase moves with ease down the length of the strand. Because human DNA is so very long (with up to 80 million base pairs in a chromosome) it unzips at multiple places along its length so that the replication…
a long chain of nucleotides 2. Messenger RNA- type of RNA that carries copies of instructions for the assembly of amino acids into proteins from DNA to rest of the cell 3. Ribosomal RNA-type of RNA that combines with proteins to form Ribosomes 4. Transfer RNA-type of RNA that carries each amino acid to a ribosome during protein synthesis 5. Transcription-synthesis of an RNA molecule from a DNA template 6. RNA Polymerase_ enzyme that links together the growing chain of RNA…
A- DNA replication DNA replication is a biological process by which a molecule of DNA is copied. This process starts at the origin of replication where the double helix of the parental DNA is being unwound by the helicase in two separated strands. Then, single-strand biding proteins bind on the unpaired strands keeping them from repairing. The topoisomerase helps relieve the strain by breaking and swiveling the DNA strands ahead of the replication fork. The primase synthesize a short stretch of…
Joey Levy AP Bio In transcription DNA is transcribed into Messenger RNA (mRNA). In translation the mRNA is translated into a polypeptide chain with the aid of Ribosomal RNA (rRNA) and Transfer RNA (tRNA). This polypeptide chain is then folded into a unique protein used in a particular cell function. Transcription occurs in the cell nucleus where DNA is housed. Think of DNA as instructions to build hardware (proteins), unfortunately, these instructions are in another language and…
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