Lecture 1-2: CELLS

Question 1

what are the 4 characteristics of cells?

Answer 1

1. cells vary in appearance
2. cells can have various functions but have the same basic chemistry
3. cells are said to have evolved from the same ancestral cell
4. cell form, function, and complex behaviour is the result of genes’ instructions

Question 2

what is the central dogma of molecular biology?

Answer 2

1. DNA is synthesized via the replication process
2. RNA is synthesized via the transcription process
3. proteins are synthesized via the translation process

Question 3

what is responsible for different gene stimulation and by default, production of different proteins?

Answer 3

DNA

Question 4

what are the fundamental features of all cells?

Answer 4

1. there is either a nucleus or nucleoid
2. cell/plasma membrane
3. cytoplasm

Question 5

which kind of cell has a nucleus and which kind of cell has a nucleoid?

Answer 5

nucleus = eukaryotic cell

nucleoid = prokaryotic cell

Question 6

describe a prokaryotic cell

Answer 6

• no membrane-bound organelles
• they are small
• have a nucleoid > nucleus
• they have a single circular chromosome
• its cytoplasm is bound by an inner and outer plasma membrane

Question 7

describe a eukaryotic cell

Answer 7

• has organelles that are membrane-bound
• it is large
• it has a nucleus > nucleoid
• has multiple linear chromosomes
• its cytoplasm is bound by a plasma membrane

Question 8

what is the role of the nucleus/nucleoid?

Answer 8

to carry genetic information for the cell

Question 9

what are the major differences between a nucleoid and a nucleus?

Answer 9

nucleoid: contains most of the cell’s genetic material and is not surrounded by a membrane

nucleus: contains all the cell’s genetic information and is surrounded by a membrane

Question 10

what organelles/non-organelles are part of the endomembrane system?

Answer 10

endoplasmic reticulum

golgi apparatus

secretory vesicles

lysosomes

Question 11

what is the endosymbiont theory?

Answer 11

the mitochondria and chloroplasts are the result of ancient bacteria take-up via phagocytosis

Question 12

what is the purpose of using a light microscope?

Answer 12

examination of cells and their components

Question 13

we would use ___ microscopy when we want to see the fine structure of a cell

Answer 13

electron

Question 14

what kind of microscope do we typically use?

Answer 14

compound microscopes

Question 15

what occurs with light microscopy without staining?

Answer 15

there is little change in amplitude but the light phase + phase differences are detectable via special lenses

Question 16

what is phase contrast?

Answer 16

a type of light microscopy that uses dyes to make transparent objects more visible

Question 17

what is differential interference contrast?

Answer 17

a type of light microscopy using dyes that allows for 3D-quality images

Question 18

what is unique about fluorescence microscopy?

Answer 18

light is absorbed at one wavelength and emitted at a longer one

Question 19

how does fluorescence microscopy work?

Answer 19

the molecule absorbs light and loses some energy as heat

the molecule then emits a photon with a longer wavelength

Question 20

describe the 2 filters in fluorescence microscopy

Answer 20

1. allows one wavelength to excite the fluorescence dye
2. blocks all light except the wavelength that was emitted by the excited dye

Question 21

why would someone use confocal fluorescence microscopy?

Answer 21

to visualize a cell’s structures from the middle rather than the top/bottom

Question 22

what are the 2 types of electron microscopy?

Answer 22

transmission

scanning

Question 23

what is resolution in terms of microscopy?

Answer 23

the ability of a microscope to distinguish between adjacent objects being separate from one another

Question 24

why is magnification different than resolution?

Answer 24

increases the number of photoreceptors that react to the stimulus you are perceiving