Laboratory Review 5 : Cell Structure and Function
LABORATORY REVIEW 5 — CELL STRUCTURE & FUNCTION
Q: What regulates the movement of molecules into and out of the cytoplasm?
A: The plasma membrane (cell membrane).
Q: Why is the plasma membrane important?
A: It regulates what enters and leaves the cell, helping maintain the cell's internal environment.
Q: What feature distinguishes a prokaryotic cell from a eukaryotic cell?
A: A prokaryotic cell lacks a membrane-bound nucleus.
Q: What is the major difference between prokaryotic and eukaryotic cells?
A: Prokaryotic cells lack a membrane-bound nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles.
Q: What structures carry out protein synthesis in both prokaryotic and eukaryotic cells?
A: Ribosomes.
Q: Name two things found in the nucleus of a eukaryotic cell.
A: DNA and the nucleolus.
Q: What is the function of the nucleolus?
A: It produces ribosomal subunits, which are used to form ribosomes.
Q: What organelle carries out photosynthesis in plant cells?
A: The chloroplast.
Q: What molecule is associated with plant cell walls?
A: Cellulose.
Q: What is the function of cellulose in the plant cell wall?
A: Cellulose provides strength and structural support.
Q: What organelle produces ATP through cellular respiration?
A: The mitochondrion.
Q: What is ATP?
A: ATP (adenosine triphosphate) is the cell's primary usable energy molecule.
Q: What is diffusion?
A: The movement of molecules from an area of higher concentration to an area of lower concentration.
Q: What is osmosis?
A: The movement of water across a selectively permeable membrane.
Q: In what direction does water move during osmosis?
A: Water moves toward the side with the higher solute concentration (lower free-water concentration).
Q: Does water move into or out of cells placed in a hypotonic solution?
A: Into the cells.
Q: Why does water move into a cell in a hypotonic solution?
A: The solution outside the cell has a lower solute concentration than the cell, so water moves into the cell by osmosis.
Q: What type of solution causes crenation of red blood cells?
A: A hypertonic solution.
Q: What happens to a red blood cell in a hypertonic solution?
A: Water leaves the cell, causing it to shrink or crenate.
Q: What type of solution causes chloroplasts to be pushed outward against the cell wall?
A: A hypotonic solution.
Q: If a solution has more hydrogen ions than hydroxide ions, where is it on the pH scale?
A: Below 7; it is acidic.
Q: What does a pH below 7 indicate?
A: An acidic solution.
Q: What does a pH of 7 indicate?
A: A neutral solution.
Q: What does a pH above 7 indicate?
A: A basic/alkaline solution.
Q: What helps maintain human blood at approximately pH 7.4?
A: Buffers.
Q: What are buffers?
A: Substances that help resist changes in pH.
Cell Structures & Functions
Q: What structures are common to both prokaryotic and eukaryotic cells?
A: Plasma membrane, cytoplasm, DNA, and ribosomes.
Q: What is the function of the nucleus?
A: It contains the cell's genetic material (DNA) and helps control cellular activities.
Q: What is the function of ribosomes?
A: They carry out protein synthesis.
Q: What is the function of the rough ER?
A: It is involved in protein synthesis and processing and has ribosomes attached to its surface.
Q: What is the function of the smooth ER?
A: It is involved in lipid synthesis and carbohydrate metabolism and lacks ribosomes.
Q: Which organelle would be abundant in cells that produce steroid hormones?
A: Smooth ER, because it is involved in lipid and steroid synthesis.
Q: What is the function of the Golgi apparatus?
A: It processes, packages, and distributes proteins and lipids.
Q: What is the function of vesicles?
A: They store and transport substances within the cell or to/from the cell membrane.
Q: What is the function of lysosomes?
A: They contain digestive enzymes that break down macromolecules and worn-out cell parts.
Q: What is the function of peroxisomes?
A: They contain enzymes involved in breaking down fatty acids and detoxifying substances such as hydrogen peroxide.
Q: What is the function of the cytoskeleton?
A: It helps maintain cell shape and assists with movement of cell parts.
Q: What is the function of centrioles?
A: They help organize microtubules, particularly during cell division, and are associated with the organization of cilia and flagella.
Q: What are the three structures unique to plant cells emphasized in this lab?
A: Cell wall, large central vacuole, and chloroplasts.
Q: What is the function of the plant cell wall?
A: It provides support, protection, and structural strength.
Q: What is the function of the large central vacuole?
A: It stores water, nutrients, and waste products and helps maintain pressure within the plant cell.
Q: What is the function of chloroplasts?
A: They carry out photosynthesis, producing sugars using light energy.
💧 OSMOSIS, DIFFUSION & TONICITY
Q: What is a hypotonic solution?
A: A solution with a lower solute concentration than the cell.
Q: What happens to a cell in a hypotonic solution?
A: Water generally moves into the cell, which can cause the cell to swell.
Q: What is a hypertonic solution?
A: A solution with a higher solute concentration than the cell.
Q: What happens to a cell in a hypertonic solution?
A: Water generally moves out of the cell, causing it to shrink.
Q: What is an isotonic solution?
A: A solution with approximately the same solute concentration as the cell.
Q: What happens to a cell in an isotonic solution?
A: There is no net movement of water into or out of the cell.
Q: What happens to a red blood cell in a hypotonic solution?
A: Water enters the cell, causing it to swell and potentially burst.
Q: What happens to a red blood cell in a hypertonic solution?
A: Water leaves the cell, causing crenation/shrinking.
Q: What happens to a red blood cell in an isotonic solution?
A: It maintains its normal shape because there is no net water movement.