Lecture 3

Question 1

Electromagnetic spectrum

Answer 1

Radio waves

Microwaves

Infrared radiation

near- infrared radiation (not in song)

Visible light

ultraviolet

X-rays

Gamma rays

Question 2

Wavelength of visible light

Answer 2

400-700 nm

Question 3

Which side of the electromagnetic spectrum is gamma rays on

Right or left
Short or long wavelength
High energy or low energy

Answer 3

Left

Short

High

Question 4

Which side of the electromagnetic spectrum is radio waves on

Right or left
Short or long wavelength
High energy or low energy

Answer 4

Right

Long

Low

Question 5

Fluorescence

Answer 5

1- electron absorbs a photon and gets excited to a higher energy state (ie. valence)

2- excited electron returns to its ground state, releasing a photo of longer wavelength (ie. lower energy)

Ex. Start at 600nm and finish at 700nm

Question 6

Common sources of fluorescence in biology

Answer 6

-intrinsic fluorescence (auto fluorescence) from specimen (ie. pigments)

• fluorescent dyes
• fluorescent proteins

Question 7

Advantage of fluorescent microscopy

Answer 7

-Allows visualization of specific structures of interest

-Can be used with living specimens (same as regular light microscopy)

Question 8

Confocal fluorescence microscopes

Answer 8

• INCREASES CONTRAST by capturing very thing slices of specimen

Does this by passing the emitted light through a tiny pinhole, which removes out of focus light

Question 9

Concepts of electron microscope

Answer 9

• higher resolution than light microscopy since electrons have very short wavelengths compared to visible light
• no “colours” since it’s not light
• requires specimen to be fixed (dead)
• specimens are stained with heavy metals, which electrons can’t pass through

Question 10

Transmission electron microscopy

Answer 10

TEM

• very thing sections are made using a microtome (fancy meat slicer basically)

-images appear as black object on white background

• light regions are where electrons passed through the sample and hit the camera
• dark regions are where electrons didn’t hit the camera

Question 11

Scanning Electron Microscopy

Answer 11

SEM

• no sectioning needed just coat the sample with a heavy metal (usually gold)
• the 3D contours of the surface are visualized by scanning an electron beam across the specimen
• typically used at much lower magnifications than TEM

Question 12

Prokaryotes examples

Answer 12

-Bacteria
-archaea

Question 13

Eukaryotes examples

Answer 13

Animals
Plants
Fungi
Protists

Question 14

How big is the average prokaryote

Answer 14

1-3 micrometers

Question 15

Prokaryotes

Answer 15

-unicellular
-small
-no membrane bound organelles
-DNA found in nucleotid
- single circular chromosome and often several circular plasmids

Question 16

Eukaryotes

Answer 16

-uni or multicellular
-small to very large
-membrane bound organelles
-DNA housed in nucleus
- one or more linear chromosomes
- Linear DNA

Question 17

Elements common to all living cells

Answer 17

1- genetic information paradigm (DNA->RNA->protein)

2- plasma membrane

3- cytoplasm

4- ribosomes

5- cytoskeleton

Question 18

Genetic information paradigm

Answer 18

DNA TO RNA TO PROTEIN

Question 19

Transcription

Answer 19

DNA to RNA using RNA polymerase

Question 20

DNA full name

Answer 20

Deoxyribonucleic acid

Question 21

RNA FULL NAME

Answer 21

Ribonucleic acid

Question 22

Translation

Answer 22

RNA to protein using ribosomes