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Cells

 

7.1 Life Is Cellular

Questions Answers

1. Where did the term “cells” come from? Who coined the term for the use it has in science today? Robert Hooke thought that they (cells) looked like monastery rooms.  They were called cells.
2. What is the cell theory? All plants and animals are made up of cells, and new cells can only be made up of old cells.
3. What are the strengths and weaknesses of compound light microscopes? What can and can’t they be used for? A strength is that it is very clear up to 1000 times the size of an original, and that they are more portable than other kinds.  A weakness is that to usually have to dye an organism to view it.  It can be used for thin things, but not thicker things.
4. What are the strengths and weaknesses of electron microscopes? What can and can’t they be used for? A strength of an electron microscope is that it has a much stronger magnification, it can be used to see DNA and viruses.  A weakness is that everything must be in a vacuum, so organisms can’t be live.
Compare AND contrast prokaryotes and eukaryotes. Name at least two similarities and three differences. SIMILARITIES

Both are cells

Both have DNA

DIFFERENCES

Prokaryotes are usually much smaller

Prokaryotes do not separate the genetic material with a membrane (no specific nucleus)

Eukaryotes are usually more complex

7.2 Cell Structure

Questions Answers

1. What is an organelle? Why don’t you think cytoplasm is considered an organelle? Organelles are organ like features inside a Cell.  Cytoplasm is just water so it does not do anything to benefit the cell.
2. Describe the function of the nucleus. Be sure to include “nuclear envelope”, “chromosomes” and “nucleolus” in your description. The purpose of a nucleus is to protect the chromosomes.  The nuclear envelope protects the nucleus, and the nucleolus is inside the nucleus.  The nucleolus’ job is to make ribosomes.                                                                                                                                                                                                                                                                                                                   
3. Compare and contrast the structure and function vacuoles and vesicles. Vacuoles have a membrane and are stagnant.  Vesicles move around and have no membrane
4. What is a lysosome? How might it work together with a vacuole or vesicle? Lysosomes are filled with digestive enzymes.  It might work together because the lysosome can help digest the nutrients in the vacuoles and vesicles.
5. Briefly describe the role of the cytoskeleton, and how it relates to centrioles. The cytoskeleton gives a cell its shape, preventing it from bending and getting hurt.  It relates to centrioles because centrioles are made up of the cytoskeleton, helping the cell
6. The ribosomes, endoplasmic reticulum and Golgi apparatus work together to produce proteins. Explain this process, distinguishing between the individual functions of each organelle The ribosomes make the acids together as planned by RNA from the nucleus.  The rough ER puts it together, and the Golgi body packages it so it can go to it’s destination.
7. Differentiate between the structure and function of the smooth and rough endoplasmic reticulum The rough ER is involved in protein synthesis.  The smooth ER is the outside and it haze enzymes that perform specialized tasks.
8a. Explain how the chloroplast and mitochondria are codependent in making energy for plant cells

8b. Why don’t animals need chloroplasts?
  1. The chloroplast takes sunlight and CO2 and makes it into C6H12O6 and H2O.  The mitochondria turns chemicals into energy, like carbs.
  2. Animals get enough energy from eating things.  
9a. Describe the lipid bilayer of the cell membrane. Why are phospholipids the ideal molecule for this structure?

9b. Why is the cell membrane considered to be a “fluid mosaic” of molecules?

  1. The outside is hydrophilic, and the inside is hydrophobic.  This is ideal so that nothing harmful can hurt the cell.  It is ideal because they don’t bond together, the just line up.
  2. They say this because there are so many different kinds of molecules and proteins.

7.3 Cell Transport

Questions Answers

1. What is diffusion? Give an example of diffusion that you might see in your everyday life. Diffusion if when molecule go down a concentration gradient and evenly spread molecules.  An example would be dye filling  a jar of water.
2. If there is a higher concentration of molecules on the outside of the cell than on the inside, will diffusion cause those molecules to travel into or out of the cell (see figure 7-15) The particles will enter the cell.
3. Compare and contrast diffusion and facilitated diffusion Both don’t take any energy to complete.  Both bring molecules through a membrane.  Facilitated diffusion has a protein bring a polar molecule through since it can’t go through the membrane.
4a. Why are aquaporins necessary?

4b. What is osmosis?

  1. Aquaporins are necessary because they allow water to flow in freely.
  2. Osmosis is diffusion but with water.  Its water making a concentration equal by passing through a membrane.
The terms “hypotonic” and “hypertonic” are simply adjectives that describe how concentrated an environment in solution is.

5a. If the inside of a cell is hypertonic compared to the outside of the cell, and the solute cannot pass through the membrane, which direction will water go? Into or out of the cell?

5b. What is meant by isotonic?

5c. Explain the importance of osmotic pressure in plants.
  1. The water will enter the cell, as in go inside of it.
  2. Isotonic means that there is an equal amount of water on both sides of the membrane.
  3. If there is too much osmotic pressure in a plant cell, the vacuole will grow and push organelles out of the cells.
6. What is active transport? What molecule do you think powers this type of transport? Active transport is when protein pumps bring molecules through the membrane against the gradient flow. ATP powers this transport.
7. Under what conditions might active molecular transport occur? Why won’t regular diffusion or active diffusion work? The cell might need lots of a certain thing.  Regular things won’t work because it goes against the concentration gradient.
8. Compare and contrast endocytosis and exocytosis. Try to think of a trick to remember the difference between these terms! Endocytosis is like the cell is eating it wraps the membrane around a large molecule and bring in into the cell.  Exocytosis is when a vesicle fuses with the membrane and explels something.

EXpels is EXocytosis

 

7.4 Homeostasis and Cells

Questions Answers

1. How do unicellular organisms maintain homeostasis? They grow and respond to the environment, they reproduce via mitosis, and they transform energy.
2a. How are individual cells within a multicellular organism different from single-celled organisms?

2b. Describe, in your own words, examples of specialized cells in animal and plants
  1. In multicellular organisms, cells are specialized to do a certain job.  In single celled, they respond to the environment directly.  
  2. In an animal, hemoglobin is an example of  a specialized cell.  In plants, pollen is an example, it has ‘wings’ so it can fly to the ground.
3. Explain the relationship between cells, tissue, organs and organ systems. Use any multicellular organism as an example in your explanation. blood cells are in veins and arteries, those are part of the heart, which is part of the circulatory system.
4. What is a receptor? Why are receptors so important? Something to which a signaling molecule can bind to.  It allows certain molecules go to places that they are needed the most by letting them only in those places.

 

 

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Al French.

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