BIOL220Z Molecular Biology Flashcards
Make sure to recap:
Life
Life domains
Main similarities/differences between genomes
Macromolecules
What are the characteristics of life?
- maintain integrity (boundaries)
- information: store, replicate, transform it into “action”
- perform and regulate metabolism (energy)
- interact/signal (with environment, other cells)
- replicate (divide)
*etc
Life: C-based and DNA-based
Describe the genome in bacterial cells
-one single circular chromosome
-smaller
-extra chromosomal elements outside of the circular chromosomes
Describe the genome in eukaryotic cells
-linear
-bigger
-mt genome and chloroplasts
Describe the origin of the present-day mitochondria
Endosymbiosis: bacterial cell engulfed by eukaryotic cell and evolve together.
Name 3 types of staining
-binding a molecule to a specific organelle structure
-binding an antibody
-GFP staining (green fluoresent)
Draw the DNA nucleic acid structure
What is a nucleoside?
Nitrogenous base and 5 carbon sugar
DNA VS RNA similarities
-bases: A,G,C
DNA vs RNA differences
DNA:
-base T
-double-stranded
-relatively stable
-information storage
-usually one
-deoxyribose sugar
RNA:
-single-stranded
-unstable
-base U
-many functions eg transport, enzymatic etc
What are Okazaki fragments?
Okazaki fragments are the short lengths of DNA that are produced by the discontinuous replication of the lagging strand.
What is ori c in e.coli?
This is the replication origin, where DNA sequences are recognised by initiator proteins
What occurs in a reverse transcriptase reaction?
Reverse transcription involves the synthesis of DNA from RNA by using an RNA-dependent DNA polymerase.
The DNA strand is not identical to the og
Name 3 important milestones in molecular biology
-“jumping genes”
-lac operon
-pcr
What was Barbara McClintock’s work about?
the discovery of transposons “the jumping genes” and the disruption caused by them on chromosome 9
What is the Lac Operon?
A classic example of an inducible operon for gene expression and control in bacteria
Who came up with PCR?
Kary Mullis et al
What is synthetic biology?
A multidisciplinary field of science that focuses on living systems and organisms, and it applies engineering principles to develop new biological parts, devices, and systems or to redesign existing systems found in nature.
How can lac Z be used as a cell reporter?
Lac Z codes for B-galactosidase and its activity serves as a marker for gene expression patterns during development eg in whole mouse embryos
Alpha helix info
3.6 amino acyl residues per turn; 2.3 Å helix radius
Perutz (1951)
Most common helix in proteins.
*
Usually about 10 aa residues
contains MALEK
Methionine, alanine, leucine, glutamate, and lysine uncharged
example of where found-myosin
310 helix
3.0 amino acyl residues per turn; 1.9 Å helix radius
Bragg et al. (1950)
Very strained structure.
Found in e.g. myoglobin and hemoglobin.
Usually very short - <4 aa residues.
example of where found - blue whale myoglobin
pi helix
4.4 amino acyl residues per turn; 4.4 Å helix radius.
Low and Baybutt (1952)
Energetically unfavourable – selected against unless functionally critical, so found near active-sites.
Usually seen as a bulge on a long alpha helix.
Usually short – 7-10 aa residues
beta helix (sheet)
Perutz (1951)
Can be parallel or antiparallel and complex structures can form.
Each strand is usually 3-10 aa in length.
Usually contains: Valine, threonine, histidine, tyrosine and isoleucine
Name an example of a protein with 310 helices
Blue whale myoglobin