Lab Practical Exam #3 Flashcards
(56 cards)
How many strands is DNA?
Two
What are the nitrogenous bases of DNA
Adenine, cytosine, guanine, and thymine
What type of sugar is in DNA?
deoxyribose
Where is DNA found?
Nucleus of eukaryotic cells, nucleoid in prokaryotic cells
What makes up a single nucleotide?
Phosphate, deoxyribose sugar, and nitrogenous base
Where does DNA replication take place?
Nucleus of eukaryotic cells, nucleoid in prokaryotic cells
What part of the cell cycle does DNA replication happen?
S (synthesis) phase
Chromatin
a complex of DNA and proteins that forms chromosomes within the nucleus/nucleoid
Centrosome
an organelle that is a microtubule which organizes (in cell division)
Centromere
Located in central area of chromosome; links a pair of sister chromatids together during cell division
A string of nucleotides would eventually code for a
amino acid/polypeptide chain
Chromatid
Half of a chromosome; ensures each new daughter cell has the correct complement of DNA at the end of cell division
What is meant by “double helix”?
A DNA molecule is made up of two linked strands that wind around each other to resemble a twisted ladder in a helix-like shape.
What are the steps of the DNA isolation that was used in the simulation?
Place test tube on ice;
transfer strawberry filtrate with pipette to test tube;
in a graduated cylinder, dissolve a spoonful of meat tenderizer into distilled water;
add meat tenderizer solution to strawberry filtrate and let it react for 10 minutes;
use pipette to add ice cold 95% ethanol along inside of tube to precipitate DNA;
with the test tube in the rack, spool precipitated DNA onto glass rod.
What was the glass rod used for? What is spooling? What direction should spooling be done in?
The glass rod was used to spool. Spooling is a method of isolating strands of DNA from a solution. Spooling is done slowly in a constant motion.
What was the ethanol used for? Why should ethanol be added slowly?
Ethanol was used because DNA is not soluble in it, therefore the DNA will precipitate.
What was the DNA isolated from in the simulation?
The DNA isolated was from strawberry filtrate.
What was the meat tenderizer used for?
To digest associated proteins that bind the DNA.
What was the detergent used for?
Detergent emulsifies cell and nuclear membranes of cells. The detergent disrupts phospholipid bilayers.
What is homogenization and when was it done in the isolation process?
Homogenization is grinding a substance. This was done first to create the strawberry filtrate.
Why were the tubes and reagents kept in an ice bath during isolation?
Cold temperature stabilizes DNA.
What does the isolated DNA look like in the tube?
Long, thin, white mucus-like strands.
Transcription: What molecule is produced by this process?
RNA
Transcription: Where in the cell does transcription take place?
Nucleus
