Title: Unit 2 Review
Course: SAT 170 Introductory Biotechnology > Section: SAT 170 Introductory Biotechnology

Q: In diffusion, molecules move toward regions of higher concentration.
- True
- False
A: False

Q: Which of the following are considered to be eukaryotes?
- protis
- fungi
- plants
- animals
- all of the above
A: all of the above

Q: Although cilia and flagella have different mechanisms of movement they both aid in cell movement, either to move things across the cell surface or to move the cell through its environment.
- True
- False
A: True

Q: Mitochondria are surrounded by a double membrane, the inner membrane of which is highly folded into structures known as cristae. What is the function of these folds?
Feedback: The many folds, or cristae, of the inner mitochondrial membrane provide more surface area for the chemical reactions of cellular respiration which ultimately leads to an increased ability to produce ATP.

Q: What are the three types of fibers present in the cytoskeleton?
Feedback: Microtubules, microfilaments and intermediate filaments make up the cytoskeleton.

Q: Compare and contrast prokaryotes and eukaryotes. Provide at least 4 differences and/or similarities.
Feedback: Prokaryotes and eukaryotes contain the same basic features that are required by all cells including DNA, cell membranes, ribosomes and cytoplasm. They both may also contain cell walls and a cytoskeleton. In contrast, prokaryotes are small and simple, primarily because they lack most of the internal structures that are present in eukaryotes. Eukaryotes are larger and more complex owing to the abundance of these internal structures which are known as membrane bound organelles. Furthermore, prokaryotes are represented by bacteria and archaea, while eukaryotes include animals, plants, fungi and protists.

Q: Ribosomes are unique structures used for the synthesis of proteins; they themselves are composed of protein subunits and ribosomal RNA (rRNA).
- True
- False
A: True

Q: What is a vesicle?
Feedback: A vesicle is a small membrane bound structure which functions primarily to move materials throughout the cell.

Q: Which organelle extracts energy from fats and sugars and uses it to make ATP?
- nucleus
- mitochondria
- cytoskeleton
- endoplasmic reticulum
- golgi complex
A: mitochondria

Q: What are the three components of cell theory?
Feedback: The three components of cell theory are that cells are the smallest unit of life; all living things are composed of cells and all cells arise from pre-existing cells.

Q: A(n)  ________ organism is composed of many cells, each of which is capable of surviving on its own.
A: colonial

Q: If red blood cells are placed in an isotonic solution, what happens? Explain your answer.
Feedback: There will be no change to a red blood cell if it is placed in an isotonic solution because the red blood cell will contain the same amount of water and solutes as the solution which means that water will neither flow out of or into the cells.

Q: Explain the role of phospholipids in the plasma membrane structure.
Feedback: Phospholipids form the phospholipid bilayer of the plasma membrane as they pair up to protect the hydrophobic “tails” toward the interior of the membrane and expose their hydrophilic “heads” toward both the cytoplasm and the extracellular fluid. This bilayer is the basic barrier of the membrane.

Q: What is the function of the golgi apparatus?
Feedback: The golgi apparatus receives the products coming from the endoplasmic reticulum. It then modifies and sorts those products before sending them to the appropriate location in the cell.

Q: Lysosomes contain __________and function to __________________________________________.
A: digestive / enzymes / break / down / unwanted / materials

Q: Explain how ATP is able to function as the energy currency for our cells.
Feedback: ATP contains three phosphate groups, each of which has a large negative charge. The bonds that hold these negatively charged phosphate groups are considered to be high energy since it takes a lot of energy to force like charged particles together. Thus, when these bonds are broken, that energy can be released.

Q: Compare and contrast simple and facilitated diffusion.
Feedback: Both simple and facilitated diffusion are methods of transport where substances are moved from areas of high concentration to areas of low concentration. In simple diffusion, these substances are able to directly cross the cell membrane since they are small enough and are able to pass through the hydrophobic core of the phospholipid bilayer. Substances that are charged or are too large will require a transport protein to facilitate the process in a method known as facilitated diffusion.

Q: What does it mean for a cell to be hypertonic to its surroundings? In which direction (into or out of the cell) do you expect water to flow? Explain your answer.
Feedback: If a cell is hypertonic to its surroundings, it means that it contains more solutes and less water than its surroundings. Since water moves from high concentration to low concentration via osmosis, water will enter the cells from the surrounding solution.

Q: Endocytosis is able to move bulk materials into the cell by forming vesicles as portions of the membrane surround the materials allowing them to enter the cell as that portion of membrane pinch off from the rest of the membrane.
- True
- False
A: True

Q: What does it mean for the plasma membrane to be selectively or semi-permeable?
Feedback: The plasma membrane is said to be selectively or semi-permeable because it only allows certain materials to cross it, thus regulating what enters and exits the cell.