TEAS 7: DNA

TEAS 7: DNA.DNA Deoxyribonucleic acid Type of nucleic acid Double-stranded helix Encodes genetic information for heredity and instructions for protein structures RNA Ribonucleic acid Type of nucleic acid Single stranded Acts as a messenger carrying instructions from DNA in nucleus for controlling the synthesis of proteins in cytoplasm Gene Segment of DNA that codes for a protein (directly encodes for mRNA) Chromatid One of two identical "sister" parts of a duplicated chromosome Half of a chromosome Chromosome A package genetic information (DNA) and proteins Organized into genes Found in the nucleus of most living cells Nucleotide Monomer of nucleic acids RNA and DNA made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base Nitrogenous base Subunit of nucleotide in DNA and RNA Contains nitrogen Include Adenine, Cytosine, Guanine, Thymine, Uracil What pairs with adenine in DNA? Thymine (T) What pairs with adenine in RNA? Uracil (U) What pairs with cytosine in both DNA and RNA? Guanine What type of bond joins base pairs in DNA? Hydrogen bonds What is a group of three nucleotides called? Codon Amino acid Monomer of protein Each codon encodes one amino acid in a peptide chain 1 amino acid can be made from different codons For example, the amino acid alanine can be made by 4 different codon sequences Codon A specific sequence of 3 adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid How many possible codons are there? 64 (Some amino acids can be made with multiple codons) How many amino acids exist? 20 What does mRNA stand for? messenger RNA (ribonucleic acid) What is the process of creating mRNA from DNA? Transcription What is the process of encoding proteins? Translation Peptide Chain A chain of amino acids to form a protein Type of polymer What do amino acids join together to form? Proteins What type of bond joins amino acids? Peptide Bonds Where are proteins made? Ribosomes mRNA carries the genetic message out of the nucleus and into the cytoplasm, where it is translated into protein on ribosomes In which direction is DNA transcribed? 5' to 3' When are chromosomes typically duplicated? Before mitosis (cell division) Are all genes the same size? No. Genes can be different sizes or lengths. Are all genes expressed at all times? No. Cells are specialized, which means that specific cells are expressing specific portions of the genetic code at different times. Plus, some genes are regulatory while other genes are "turned off" because they are not needed. It's like the genetic library is enormous, but only select books are in use at any given time. What does a regulatory gene do? A regulatory gene encodes for a protein that can turn other genes on or off Are chromosomes completely made of genetic material? No. Chromosomes contain protein which acts as a structural support for the DNA What is a phosphate group? It's part of the nucleotide backbone in DNA and RNA