Cell Introductions

Question 1

What are microscopes?

Answer 1

Microscopes are devices that produce a magnified image of objects too small to be seen directly by eyes.

Question 2

Define resolution

Answer 2

Resolution is the ability of a microscope to distinguish details of a specimen or sample

Question 3

Pros and cons of electron microscope compared to light microscope

Answer 3

Pros
- It has higher magnification
- High resolving power

Cons
- Expensive to use
- Requires cells to be killed chemically
- No movement can be seen
- Without stain, or dye, no color
- High voltage electric current is required
- Specimen preparation usually takes few days

Question 4

What is stain?

Answer 4

Stains are colored substances that bind to specific chemicals but not others

Question 5

What is fluorescence?

Answer 5

Fluorescence is when a substance absorbs light and than re-emits it at a longer wavelength, creating particularly bright images.

Question 6

What is Immunofluorescence?

Answer 6

Immunofluorescence is a technique that uses fluorescently stained antibodies to bind to specific target proteins within a cell, the protein tagged can be located and tracked as it moves in the cell.

Question 7

What is freezes fracture electron microscopy?

Answer 7

Technique used to produce images of surfaces within cells.
Samples are put under low temperature, rapidly freezes.
Then, it is etched some ice at the surface is removed by vaporization.
You have a replica of the fracture surface.
Replica is removed and viewed with an electron microscope

Question 8

Cryogenic Electron Microscopy?

Answer 8

It is mostly used for researching proteins, it is a solution with the molecule of interest. It can create images of how proteins may change as they work.

Question 9

Explain two distinct types of cells

Answer 9

1) Prokaryotic - no membrane bound nucleus or organelles, single celled and is small

2) Eukaryotic - Has a membrane bound nucleus and organelles, may be single celled or multi cellular.

Question 10

What structures are common in ALL cells?

Answer 10

1. Plasma membrane
2. Cytoplasm
3. DNA
4. Ribosomes

Question 11

7 Basic functions of life?

Answer 11

MR. SHENG

Metabolism - Chemical reaction in body that turns foods into energy. Life sustaining chemical reactions in organisms.

Reproduction - Producing of offspring, either sexually or asexually

Sensitivity - Essential movements of living things

Homeostasis - Living things maintain a stable internal environment

Excretion - Removal of waste products

Nutrition - Exchange gases and materials with the environment

Growth - Ability to move and change shape or size

Question 12

Define atypical cell

Answer 12

A cell that does not disprove the cell theory but does not fit into our typical idea of cells. Do not fit the general trend

Question 13

Examples of atypical cell

Answer 13

Red blood cell - no nucleus

Skeletal muscle - one plasma membrane but many nuclei, their own nucleus fuse together to form long muscle fibers

Question 14

Cell size as an aspect of specialization?

Answer 14

The size of cells can vary significantly in multicellular organisms in order to optimize the specific function of a cell.

Question 15

Examples of cell size as an aspect of specialization

Answer 15

Red blood cells - needs to squeeze through narrow capillaries and is extremely small and thin

Motor neurons - needs to transmit signals throughout the body and the extending part

Question 16

What happens if the ratio is too small?

Answer 16

If the ratio is too small, the cell won’t be able to keep up with the demand for the chemical reactants and waste will accumulate.

Metabolic reactions in cells produce heat so if the ratio is too small it will cause the cell to overheat.

Question 17

What depends in the surface area if the cell membrane?

Answer 17

Absorbing of the needed substances of the call and removing of any waste produced. This is occurred by movement through the cell membrane