BIO EXAM 2 11. Cell and Molecular Biology Methods Squarecc

Cell Theory in its modern form includes all of the following postulates except __________________

A)

All organisms are composed of one or more cells.

B)

Cells are the smallest living things.

C)

Cells arise only by division of a previously existing cell.

D)

All cells contain nucleus

E)

Cell is the unit of life.

D)

All cells contain nucleus

Not necessarily; some cells can be anaerobic or facultatively aerobic based on oxygen levels in the environment. They can survive through glycolysis to form ATP.

You would be wasting your time if you were trying to use a light microscope to see_______

A)

viruses

B)

animal cells

C)

bacteria

D)

yeast cells

E)

chloroplasts

A)

viruses

The other choices are composed of many different monomers and are highly complex. The ribosome resides inside cells and is much smaller than what can be visualized in a light microscope.

In agarose gel electrophoresis, DNA or RNA fragments migrate towards ___________ end of the gel plate because of their____________.

A)

the neutral….. charge

B)

the anode ….. size

C)

the cathode ….. charge

D)

the anode ….. charge

E)

the neutral ….. size

D)

the anode ….. charge

The cathode in gel electrophoresis is negatively charged. RNA and DNA are negatively charged overall and are loaded into the cathode end of the gel. They move toward the positive end, anode (that attracts anions) because of negative charge.

Arrange the following sequence of procedures in the proper order in this experiment done to determine proteins present in pea plants during germination.

1. Load the proteins in polyacrylamide gel electrophoresis and separate them

2. Break the cells by grinding them in liquid nitrogen and suspending in a buffer

3. Select a suitable tissue to isolate proteins expressed only during germination

4. Centrifuge the broken cells to purify proteins from other molecules

A)

1,3,2,4

B)

3,2,1,4

C)

2,4,1,3

D)

3,2,4,1

E)

2,4,3,1

D)

3,2,4,1

First step is to identify where you want the cells from. Then you have to break the cells to retrieve the proteins and centrifuge the components to isolate the proteins. Then you load the gel with the proteins and run it to separate according to size and charge.

Which of the following molecules do not have any charges on them so that they cannot be separated by gel electrophoresis? There may be more than one answer.

Select all that apply

A)

Carbohydrates

B)

Trigylcerides

C)

Proteins

D)

DNA

E)

RNA

F)

Carotenoids

A)

Carbohydrates

B)

Trigylcerides

F)

Carotenoids

Lipids and carbohydrates do not have any charges associated with them, making it difficult to separate them by gel electrophoresis. What methods are good for separating such molecules?

gas chromatography, mass spectrometry, high performance liquid chromatography

Lipids: Chromatography (TLC, GC, HPLC), mass spectometry

Carbohydrates: Calorimetric, Gas Chromatography, Mass spectometry

You are working for the CDC and investigating a toxic E. coli contamination in lettuce.

Which method(s) would be useful to identify the toxic E. coli?

 

PCR, light microscopy, isolate the bacteria, view under a microscope and look for the proteins specific to ecoli

A sewage line broke and contaminated drinking water source of a rural town. You are asked to investigate if there is any bacterial contamination after fixing the sewage leak. What methods would you follow?

Light microscope, thin layer chromatography

Which of the following methods would allow you to observe the 3-D structures of small proteins?

A)

Light Microscopy

B)

Electron Microscopy

C)

HPLC

D)

X-ray Crystallography

E)

Polyacrylamide Gel Electrophoresis

B)

Electron Microscopy

D)

X-ray Crystallography