Cell Biology Test one

Cell Biology Test one - Cell Biology Test one-Outline for...

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Cell Biology Test one -----Outline for domination 1) Describe the concept of heredity : heredity is the passing of one organism’s traits/genes to its offspring. 2) Describe the role of DNA in heredity : All cells store their hereditary matter as deoxyribonucleic acid. It contains the blueprints for the construction of the entire organism. 3) Describe the basic structure of DNA and how it functions to record information important in heredity: DNA (deoxyribonucleic acid) is composed of subunits called nucleotides. Each consists of a sugar-phosphate molecule with a nitrogenous base. There are only four types of possibly bases in DNA--- Two of the bases include cytosine (C), and thymine (T),--Thymine and cytosine are both pyrimidines (having a single carbon-nitrogen ring). Guanine (G) and Adenine (A) the other two bases have double rings and are classified as purines. ---------------------- The structure of DNA is a double helix (double stranded). A single DNA strand consists of nucleotides joined together by sugar-phosphate linkages. 4) Describe the complementarity of bases and how this is important in DNA function: In DNA each strand pairs to its corresponding strand by bases---A pairs with T and G pairs C. Through template polymerization the sequence of nucleotides in an existing DNA strand controls the sequence in which nucleotides are joined together in a new DNA strand. STRAND HAS a backbone with opposite directionality. PYRIMIDINES pair with PURINES. Feature DNA RNA Sugar Deoxyribose Ribose Types of nitrogenous bases A,T,C,G A,U,C,G #’s of nitrogenous bases Averages 10 8 base pairs 70-10,000 bases Number of nucleotide chains Two---double helix One Site of action Functions in nucleus; cannot leave Leaves nucleus; functions mainly in cytoplasm Function Codes for synthesis of RNA and protein Carries of out the instructions in DNA; assembles proteins 5) Compare and contrast the structures of DNA and RNA: RNA like DNA is composed of nucleotides which contain a sugar phosphate group attached to a nitrogenous base. However the sugar used in RNA is ribose instead of Deoxyribose sugar, and RNA is single stranded not double stranded. Through transcription RNA is synthesized using DNA as its template however base pairing is slightly different in that Adenine pairs with Uracil, still G with C.
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6) Describe the role of RNA in cell functioning: All cells translate RNA into protein the same way. The information in the sequence of messenger RNA molecule is read out in groups of three nucleotides at a time: each triplet of nucleotides or codon specifies/ codes for a specific amino acid in a corresponding protein. Several codons correspond to the same amino acid. This code is read out by transfer RNAs each tRNA becomes attached at one end to a specific amino acids----and displays at its other its anti-codon that enables it to recognize----a particular codon or subset of codons----this translation occurs in the ribosome-----made of two main chains of RNA called ribosomal RNAs. Protein synthesis
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This note was uploaded on 02/09/2011 for the course BIOL 320 taught by Professor Bennet during the Spring '11 term at Indiana.

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Cell Biology Test one - Cell Biology Test one-Outline for...

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