1. Describe the structure of a nucleotide. A nucleotide is a sugar molecule that has 3 parts including a simple sugar, a phosphate group and a nitrogenous base. Nucleotides join together forming long chains, with the phosphate group of nucleotide bonding to the deoxyribose sugar of an adjacent nucleotide. 3. Explain why the structure of a DNA molecule is often described as a zipper. The structure of a DNA molecule is often described as a zipper because it is made of tow chains of nucleotides held together by nitrogenous bases. Just like the teeth of a zipper hold the two sides of the zipper together, the nitrogenous bases of the nucleotides hold the two strands of DNA together. 4. How does DNA hold information? The DNA holds information in the sequence of nucleotides. The different sequences each carry different information
Glencoe pg. 295 #1-4, pg. 301 #1
1. How does the DNA nucleotide sequence determine the amino acid sequence in a protein? The sequence of nucleotides in each gene contains information for assembling the string of amino acids that make up a single protein. The RNA molecules take instructions from DNA on how the protein should be assembled and then they assemble the protein. 2. What is a codon, and what does it represent? A codon is a group of nitrogenous bases in mRNA that code for one amino acid. They represent the amino acid. 3. What is the role of tRNA in protein synthesis? The role of tRNA is to bring the dissolved amino acids in the cytoplasm to the ribosomes. Each tRNA molecule only attaches to one type of amino acid and it only carries the amino acid that anticodon specifies. 4. Compare DNA replication and transcription. DNA replication is the transcription results in the formation of one single stranded RNA molecule rather than a double stranded BNA molecule.