Question 11 Guanine from one nucleotide strand will always pair with cytosine from the other strand using three hydrogen bonds and adenine from one strand will pair with thymine from the other using two hydrogen bonds.
Question 17 The complementary nature of the two chains of nucleotides that make up the DNA molecule. If the original chain of nucleotides has a nitrogen base sequence of CATCAA the other assembled beside it would be GTAGTT.
DNA Helicase Polymerase Red color is the new strand,blue color the original strand. The red box is showing the complementary bases mentioned in the last slide.
Question 18 It proceeds in opposite directions on each original strand. Replication begins simultaneously at many points along one original strand and at just one point on the other original strand.
DNA Helicase Polymerase Direction of Replication Polymerase
Question 19 Two new exact copies of the original DNA molecule. Each molecule has one original strand of nucleotides and a copied complementary strand.
Original DNA Original DNA strands opened up Two new molecules of DNA each with one old and one new strand
Question 26 The sugar in RNA is ribose in DNA it’s deoxyribose. RNA has the nitrogen base Uracil (U) instead of Thymine as in DNA
Question 27 Messenger RNA (mRNA) - carries genetic information from DNA in the nucleus to the ribosome.
Ribosomal RNA (rRNA), combines with proteins to make up the two subunits of a ribosome
Question 27 (continued) Transfer RNA (tRNA) -each binds to a particular amino acid and brings it to the ribosome
Question 28 The process by which genetic information is copied from DNA to mRNA
Question 29 RNA polymerase. Makes RNA copies of specific sequences of DNA
Question 30 A specific region of DNA that marks the beginning of that part of the DNA chain that will be transcribed. The DNA unwinds and the RNA polymerase binds at a particular site on the DNA. The initial binding site is called the " promoter region ".
Question 31 That portion of the DNA molecule (only one of the two nucleotide strands) that is copied by RNA polymerase.
Question 34 The termination signal - a specific sequence of nucleotides on the template that marks the end of a gene. Template strand DNA
Question 35 The RNA polymerase Template strand DNA Termination signal
Question 36 Transcripts - different types of RNA molecules including mRNA, tRNA, and rRNA. The mRNA may have further processing occur. Noncoding regions called introns are removed and the remaining coding regions called exons are spliced together.
Question 41 The codon that causes a ribosome to start translating an mRNA molecule into a protein. It is always the nitrogen base sequence AUG. The codons that cause translation to cease. There are three.
Question 46 A sequence of three nitrogen bases on the tRNA molecule that are complementary to a codon on a mRNA molecule. It actually pairs with the codon on mRNA.
Question 47 The complementary base pairing between codons on mRNA and anticodons on tRNA anticodon codons
Question 48 Composed of rRNA and proteins. Make up 2 subunits. Found free in the cytosol and attached to the endoplasmic reticulum.
Question 49 Ribosomes found free in the cytosol produces proteins used inside the cell. Those attached to the E.R. produce proteins used in the cell membrane or outside of the cell.
Question 50 One site holds a mRNA transcript so its codons can be read by tRNA. The other two sites (P and A sites) hold tRNA molecules so that their attached amino acids can be bonded to the growing chain. mRNA holding site
Question 51 Methionine. Only initially. It may be removed later. mRNA binding site Start codon