Chapter 3: The Cellular Level of Organization Study Guide Spring 2025 PDF

**Chapter 3: The Cellular Level of Organization Study Guide** \*\*DO NOT GOOGLE ANSWERS! Sometimes you will find inconsistencies between the textbook material and the internet. Exam questions will be based on TEXTBOOK material! \*\*Any Notes and/or explanations that are written in the study guides...

**Chapter 3: The Cellular Level of Organization Study Guide** \*\*DO NOT GOOGLE ANSWERS! Sometimes you will find inconsistencies between the textbook material and the internet. Exam questions will be based on TEXTBOOK material! \*\*Any Notes and/or explanations that are written in the study guides are testable material \*\*\*You do NOT have to submit your answers to me. **An Introduction to Cells** 1\) What are the two general classes of cells? Briefly describe each. **Section 3-1** The plasma membrane separates the cell from its surrounding environment and performs various functions 1\) The plasma membrane is a *phospholipid bilayer* (contains two layers \[*bilayer*\] of phosphorylated lipids \[*phospholipids*\]) that has *hydrophobic* and *hydrophilic* properties. How are the two layers of phospholipids arranged in the plasma membrane due to those properties? 2\) There are various types of membrane proteins that perform specific functions. What body system uses *recognition proteins* to determine if a cell is abnormal or normal? 3\) What is the function of cell membrane *carrier proteins*? **Section 3-2** Organelles within the cytoplasm perform particular functions 1\) What is the difference between the *cytosol* and the *cytoplasm*? 2\) Use the information in ***Spotlight Figure 3-1 Anatomy of a Model Cell*** to describe the structure and function of the following cell structures: NOTE: Ensure that you read the textbook material about each of these cell components to help understand their functions. Microvilli Smooth ER Centrioles Golgi apparatus Cilia Lysosomes Flagella Peroxisomes Ribosomes Mitochondria Rough endoplasmic reticulum (RER) Proteosomes Nucleus Nucleolus **Section 3-3** The nucleus contains DNA and enzymes essential for controlling cellular activities 1\) What is a *nucleosome*? Briefly describe its function. 2\) What is the difference between *chromatin* and *chromosomes*? Which would you find in non-dividing cells? Which would you find in dividing cells? 3\) Certain areas of DNA contain three consecutive nitrogenous bases called *triplets*. What does each triplet represent? 4\) A gene is the functional unit of heredity. What does a gene's sequence of nucleotides specify? **Section 3-4** DNA controls protein synthesis, cell structure, and cell function 1\) In general, what occurs during *transcription*? 2\) What is the function of *mRNA*? 3\) What is the name of the DNA strand that contains triplets that are used as a template for mRNA synthesis? 4\) What enzyme is necessary to transcribe DNA into RNA? 5\) What RNA nucleotide is added in place of thymine in the synthesized RNA strand? 6\) What is a *codon* and what does it code for? 7\) What is the difference between an *intron* and an *exon*? 8\) In general, what occurs during *translation*? 9\) What is the function of tRNA? 10\) What is an *anticodon*? What type of RNA contains an anticodon? 11\) What is the sequence of the mRNA start codon? 12\) When does elongation of the mRNA strand terminate? **Section 3-5** Diffusion is a passive transport mechanism that assists membrane passage of solutes and water 1\) What is the function of a *selectively permeable membrane*? 2\) What is *diffusion*? Is it an active or passive process? 3\) What is *osmosis*? Is it an active or passive process? 4\) What is the difference between *diffusion* and *osmosis*? 5\) *Define osmolarity*. 6\) What occurs if you place a cell in an isotonic solution? A hypotonic solution? A hypertonic solution? (Remember: hypo swells, hyper shrinks, and iso stays the same). Figure 3-17 is a great visual representation of the concept. A diagram of a cell structure Description automatically generated 7\) Which solution from \#6 will result in hemolysis of a red blood cell? Which would result in crenation (shrinking) of a red blood cell? **Section 3-6** Carrier-mediated and vesicular transport assist membrane passage of specific substances 1\) What is *carrier-mediated transport*? What is *vesicular transport*? 2\) What is the difference between *symport* (cotransport) and *antiport* (countertransport)? (Remember: **[s]**ymport moves substances in the **[s]**ame direction and antiport moves substances in the opposite direction) 3\) What is *facilitated diffusion*? Is it an active or passive process? 4\) The *sodium-potassium exchange pump* uses primary active transport. For each ATP that is hydrolyzed to ADP how many sodium ions are moved? Are they moved into or out of the cell? How many potassium ions are moved? Are they moved into or out of the cell? **Note**: You will learn about the importance of the sodium-potassium exchange pump later this semester when we learn about a physiological process call an *action potential*. 5\) What is the difference between *pinocytosis* and *phagocytosis*? 6\) What is the difference between endocytosis and exocytosis? \[Remember: endocytosis brings substances into a cell (**[en]**do **[en]**ter), while exocytosis releases substances from the cell (**[ex]**o **[ex]**it)\] **Section 3-7** The membrane potential of a cell results from the unequal distribution of positive and negative charges across a plasma membrane 1\) What is the unit of measurement used to express the potential difference across the cell membrane? **Section 3-8** Stages of the cell life cycle include interphase, mitosis, and cytokinesis 1\) What occurs during the *S phase* of interphase? 2\) What *enzyme* is used during DNA replication that links nucleotides using covalent bonding? 3\) What occurs during *cytokinesis*? **Section 3-9** Several factors regulate the cell life cycle 1\) What is the function of *MPF* (M-phase promoting factor; also known as maturation-promoting Factor)? **Section 3-10** Abnormal cell growth and division characterize tumors and cancers 1\) What is the difference between *benign* and *malignant* tumors? 2\) What is an *oncogene*? 3\) What is a *carcinogen*? 4\) Define *metastasis*. **Section 3-11** Cellular differentiation is cellular specialization as a result of gene activation or repression 1\) What occurs in a cell if a gene is "*turned off*" (functionally eliminated)? 2\) What is *cellular differentiation*? Note: It is important to know that even though all nucleated body cells possess the exact same genes, not all cells perform the same functions due to ***activating and repressing genes***.