Biology Lab Techniques

Question 1

Centrifugation

Answer 1

Spins and separates liquified cell homogenates into layers based on density

Nuclei (most dense)–> mitochondria/lysosome/peroxisome—> microsomes (inner membranes from ER)/ vesicles—–> Ribosomes/viruses/large macromolecules

Question 2

Density Centrifugation

Answer 2

Continuous layer of sediment

Question 3

Differential centrifugation

Answer 3

Density and shape dependent

Based on speed the macromolecule travels at

Spin, take dense pellet, and spin again

Question 4

Karyotyping

Answer 4

Technique allowing visualization of cell’s chromosomes

Usually performed during metaphase

Question 5

RE

Answer 5

Enzymes from bacteria used to cut specific sequences of DNA

Leaves single stranded sticky ends

Question 6

Endonucleases

Answer 6

Cleave phosphodiester backbone internally to remove NT

Cuts internally

Question 7

Exonucleases

Answer 7

Cut out NTs from one end

Result in freed nucleosides

Question 8

Gel Electrophoresis

Answer 8

Seperates DNA molecules based on size

DNA first cut with RE

Also used to seperate proteins and amino acids (smaller= faster)

Move from cathode (negative)—–> anode (positive)

Question 9

PCR

Answer 9

Involved in DNA replication

Amplifies DNA

Sample mixed with Taq polymerase (heat stable form of DNA polymerase) and nucleotides and primers

Question 10

cDNA

Answer 10

Complementary DNA

Way to get DNA without introns

Can close human gene using bacteria

Fully processed mRNA is extracted from cells and placed with the enzyme reverse transcriptase

turns mRNA into DNA

Question 11

Precision

Answer 11

Closeness of 2+ measurements to each other

Question 12

Accuracy

Answer 12

Closeness of a measure value to a standard or known value

Question 13

ELISA

Answer 13

Enzyme linked immunosorbent assay

Uses an enzyme to quantify or detect the presence of a give substrate (i.e Ab or antigens)