Question

NEED HELP, I HAVE AN F IN THIS CLASS, ONLY 15 POINTS!!

1. How does the folded membrane in the structure of mitochondria and endoplasmic reticulum impact the job they do?
2. What is the role of the cell membrane?
3. Explain the difference between passive and active transport.
4. What would be the effect of a cell if it was placed in a hypotonic solution, hypertonic solution, and an isotonic solution? Explain each.

Identify which type of microscopes are described below:

5. Used in an everyday setting to view living and nonliving specimens
6. Uses electron beams to project a 3D image of the surface of a specimen
7. Uses electron beams to enhance, magnify, and project a 2D image of internal images of a cell with the greatest detail of all microscopes
8. Lowest magnification used in class to study anatomical features

Answer 1

1. The folding of the inner membrane increases the surface area inside the organelle. Since many of the chemical reactions happen on the inner membrane, the increased surface area creates more space for reactions to occur. If you have more space to work, you can get more work done.

2. Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. ... Specialized proteins in the cell membrane regulate the concentration of specific molecules inside the cell.

3. There are two major ways that molecules can be moved across a membrane, and the distinction has to do with whether or not cell energy is used. Passive mechanisms like diffusion use no energy, while active transport requires energy to get done.

4. Isotonic solutions have the same water concentration on both sides of the cell membrane. Blood is isotonic. Hypertonic solutions have less water ( and more solute such as salt or sugar ) than a cell. ... A single animal cell ( like a red blood cell) placed in a hypotonic solution will fill up with water and then burst.

5. What is the compound light microscope? The simple microscope is a one-lensed microscope first used for biological purposes by Anton Van Leeuwenhoek...it views living specimen, on a 2D basis. Used today for simple observations.

6. A scanning electron microscope scans a beam of electrons over a specimen to produce a magnified image of an object. That's completely different from a TEM, where the beam of electrons goes right through the specimen. Electrons are fired into the machine.

7.Transmission electron microscope (TEM) is another powerful technique to evaluate the internal structure of the nano-particles, as illustrated in Chapter 2. A high energy beam of electrons is transmitted through a very thin sample and usually provides two-dimensional images. The radiation source is an electron gun.

8. Most educational-quality microscopes have a 10x (10-power magnification) eyepiece and three objectives of 4x, 10x and 40x to provide magnification levels of 40x, 100x and 400x. Magnification of 400x is the minimum needed for studying cells and cell structure.