Anatomy & Physiology: Cell Structure, Membrane Transport, Cell Cycle, and Protein Synthesis Study Guide

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Q1. What does the cell theory state?

Background

Topic: Cell Theory

This question tests your understanding of the foundational principles that define what a cell is and its role in living organisms.

Key Terms:

Cell theory
Organism
Basic unit of life

Step-by-Step Guidance

Recall the three main tenets of cell theory. Think about what the theory says about the structure and function of all living things.
Consider how the theory addresses the origin of new cells.
Reflect on why the cell is considered the basic unit of life.

Try solving on your own before revealing the answer!

Final Answer:

The cell theory states that: (1) All living things are composed of one or more cells; (2) The cell is the basic unit of structure and function in living things; (3) All cells arise from pre-existing cells.

Q2. What are the 3 main parts of the cell?

Background

Topic: Cell Structure

This question is about identifying the fundamental structural components of a typical eukaryotic cell.

Key Terms:

Plasma membrane
Cytoplasm
Nucleus

Step-by-Step Guidance

Think about the outer boundary of the cell and what it is called.
Consider what fills the space inside the cell, excluding the nucleus.
Identify the structure that contains the cell's genetic material.

Try solving on your own before revealing the answer!

Final Answer:

The three main parts of the cell are the plasma (cell) membrane, the cytoplasm, and the nucleus.

Q3. What is meant by the fluid mosaic model?

Background

Topic: Cell Membrane Structure

This question tests your understanding of how the plasma membrane is structured and how its components interact.

Key Terms:

Phospholipid bilayer
Proteins
Fluid mosaic model

Step-by-Step Guidance

Recall what the "fluid" part of the model refers to in terms of membrane movement.
Think about what the "mosaic" part describes regarding the arrangement of proteins and lipids.
Consider how this model explains the dynamic nature of the cell membrane.

Try solving on your own before revealing the answer!

Final Answer:

The fluid mosaic model describes the plasma membrane as a flexible, dynamic structure with proteins embedded in or attached to a shifting phospholipid bilayer, resembling a mosaic.

Q4. How does the arrangement of hydrophilic and hydrophobic regions create a semipermeable membrane that regulates contents flowing into and out of the cell?

Background

Topic: Membrane Permeability

This question is about how the structure of the phospholipid bilayer allows selective movement of substances.

Key Terms:

Hydrophilic (water-loving) heads
Hydrophobic (water-fearing) tails
Semipermeable membrane

Step-by-Step Guidance

Recall the structure of a phospholipid and how they arrange themselves in the membrane.
Think about which molecules can pass through the hydrophobic core and which cannot.
Consider how this arrangement allows the membrane to be selective about what enters and exits the cell.

Try solving on your own before revealing the answer!

Final Answer:

The hydrophilic heads face outward toward water, while hydrophobic tails face inward, creating a barrier that allows only certain substances (like small, nonpolar molecules) to pass freely, making the membrane semipermeable.

Q5. What are the main types of cell junctions? How do they function?

Background

Topic: Cell Junctions

This question tests your knowledge of how cells connect and communicate with each other.

Key Terms:

Tight junctions
Desmosomes
Gap junctions

Step-by-Step Guidance

List the three main types of cell junctions found in animal tissues.
For each type, recall its primary function (e.g., sealing, anchoring, communication).
Think about where in the body you might find each type of junction.

Try solving on your own before revealing the answer!

Final Answer:

The main types are tight junctions (seal cells together), desmosomes (anchor cells), and gap junctions (allow communication between cells).

Q6. What is cytosol? What is an organelle?

Background

Topic: Cell Components

This question is about distinguishing between the fluid part of the cytoplasm and the specialized structures within the cell.

Key Terms:

Cytosol
Organelle

Step-by-Step Guidance

Define cytosol and consider what it contains.
Define organelle and think of examples.
Differentiate between the two in terms of structure and function.

Try solving on your own before revealing the answer!

Final Answer:

Cytosol is the fluid portion of the cytoplasm, while organelles are specialized structures within the cell that perform specific functions.

Q7. What are the two basic methods of membrane transport? What are the passive processes? What are the active processes? What is an aquaporin?

Background

Topic: Membrane Transport

This question tests your understanding of how substances move across the cell membrane, both with and without energy.

Key Terms and Concepts:

Passive transport (no energy required)
Active transport (requires energy)
Aquaporin (water channel protein)

Step-by-Step Guidance

Identify the two main categories of membrane transport.
List examples of passive processes (e.g., diffusion, osmosis, facilitated diffusion).
List examples of active processes (e.g., active transport, endocytosis, exocytosis).
Define aquaporin and its role in the cell membrane.

Try solving on your own before revealing the answer!

Final Answer:

The two basic methods are passive and active transport. Passive processes include diffusion, osmosis, and facilitated diffusion. Active processes include active transport, endocytosis, and exocytosis. Aquaporins are channel proteins that facilitate water movement across the membrane.

Q8. What is osmosis? Isotonic? Hypotonic? Hypertonic?

Background

Topic: Osmosis and Tonicity

This question is about the movement of water across membranes and the effects of different solute concentrations.

Key Terms:

Osmosis
Isotonic
Hypotonic
Hypertonic

Step-by-Step Guidance

Define osmosis in terms of water movement and concentration gradients.
Explain what happens to a cell in an isotonic solution.
Describe the effects of hypotonic and hypertonic solutions on cells.

Try solving on your own before revealing the answer!

Final Answer:

Osmosis is the diffusion of water across a semipermeable membrane. Isotonic means equal solute concentration; hypotonic means lower solute concentration outside the cell (cell swells); hypertonic means higher solute concentration outside (cell shrinks).

Q9. What is facilitated diffusion as a passive method of membrane transport?

Background

Topic: Facilitated Diffusion

This question is about how certain molecules cross the membrane with the help of proteins, without energy input.

Key Terms:

Facilitated diffusion
Carrier proteins
Channel proteins

Step-by-Step Guidance

Define facilitated diffusion and how it differs from simple diffusion.
Identify the types of molecules that require facilitated diffusion.
Explain the role of carrier and channel proteins in this process.

Try solving on your own before revealing the answer!

Final Answer:

Facilitated diffusion is the passive movement of molecules across the membrane via specific transport proteins, without energy input, for substances that cannot diffuse directly through the lipid bilayer.

Q10. What is the sodium-potassium (Na–K) pump as a method of active transport? How does it work? Be able to match/put in order or label the picture of the three steps of this process!

Background

Topic: Active Transport Mechanisms

This question is about the Na–K pump, a key protein that moves ions against their concentration gradients using ATP.

Key Terms and Formula:

Active transport
ATP (adenosine triphosphate)
Na+ and K+ ions

Step-by-Step Guidance

Recall that the Na–K pump moves sodium and potassium ions in opposite directions across the membrane.
Identify the number of Na+ ions pumped out and K+ ions pumped in per cycle.
Think about the role of ATP in powering this process.
Consider the sequence of steps: binding of ions, ATP hydrolysis, conformational change, and release of ions.

Try solving on your own before revealing the answer!

Final Answer:

The Na–K pump actively transports 3 Na+ ions out of the cell and 2 K+ ions into the cell using energy from ATP. The process involves binding of Na+, phosphorylation by ATP, conformational change, release of Na+, binding of K+, dephosphorylation, and return to original shape to release K+ inside.

Q11. As a form of active transport, what is exocytosis and endocytosis?

Background

Topic: Bulk Transport

This question is about how cells move large particles or volumes of substances across the membrane using vesicles.

Key Terms:

Exocytosis
Endocytosis
Vesicle

Step-by-Step Guidance

Define exocytosis and describe what is being transported.
Define endocytosis and its subtypes (phagocytosis, pinocytosis, receptor-mediated).
Consider the direction of movement (into or out of the cell) for each process.

Try solving on your own before revealing the answer!

Final Answer:

Exocytosis is the process of moving substances out of the cell via vesicles, while endocytosis is the process of bringing substances into the cell using vesicles.

Q12. What is the cell cycle? What are the major phases?

Background

Topic: Cell Cycle

This question is about the sequence of events that a cell goes through from one division to the next.

Key Terms:

Cell cycle
Interphase
Mitotic (M) phase

Step-by-Step Guidance

Define the cell cycle and its purpose.
List the two main phases: interphase and mitotic phase.
Break down interphase into its subphases (G1, S, G2).
Identify what happens during the mitotic phase.

Try solving on your own before revealing the answer!

Final Answer:

The cell cycle is the series of events in a cell's life, consisting of interphase (G1, S, G2) and the mitotic (M) phase (mitosis and cytokinesis).

Q13. What are the phases of mitosis? What occurs in each phase of mitosis?

Background

Topic: Mitosis

This question is about the process of nuclear division and the events that occur in each stage.

Key Terms:

Prophase
Metaphase
Anaphase
Telophase

Step-by-Step Guidance

List the four main phases of mitosis in order.
For each phase, recall the key events (e.g., chromosome condensation, alignment, separation, reformation of nuclei).
Think about how you would identify each phase under a microscope.

Try solving on your own before revealing the answer!

Final Answer:

The phases are prophase (chromosomes condense), metaphase (chromosomes align at the center), anaphase (sister chromatids separate), and telophase (nuclear envelopes reform).

Q14. What are the three stages of interphase? When does DNA replication occur?

Background

Topic: Interphase and DNA Replication

This question is about the preparation steps a cell takes before division, including when DNA is copied.

Key Terms:

G1 phase
S phase
G2 phase
DNA replication

Step-by-Step Guidance

List the three stages of interphase in order.
Describe the main event of each stage.
Identify during which stage DNA replication occurs.

Try solving on your own before revealing the answer!

Final Answer:

The three stages are G1 (cell growth), S (DNA replication), and G2 (preparation for mitosis). DNA replication occurs during the S phase.

Q15. What does semiconservative mean in regard to DNA replication? Be able to take an example template strand and make a new DNA strand with correct complementary base pairs.

Background

Topic: DNA Replication

This question is about the mechanism of DNA replication and how new strands are formed using existing strands as templates.

Key Terms:

Semiconservative replication
Complementary base pairing
Template strand

Step-by-Step Guidance

Define semiconservative replication and what it means for the new DNA molecules.
Recall the base pairing rules: A pairs with T, C pairs with G.
Given a template strand, write the complementary sequence using the base pairing rules.

Try solving on your own before revealing the answer!

Final Answer:

Semiconservative means each new DNA molecule has one old (template) strand and one new strand. For a template TACTGC, the new strand is ATGACG.

Q16. What is cytokinesis? When does it usually start? How is it recognized as happening during this phase of cell division?

Background

Topic: Cytokinesis

This question is about the division of the cytoplasm and how it is distinguished from mitosis.

Key Terms:

Cytokinesis
Cleavage furrow
Telophase

Step-by-Step Guidance

Define cytokinesis and its role in cell division.
Identify when cytokinesis typically begins in relation to mitosis.
Describe the physical changes in the cell that indicate cytokinesis is occurring.

Try solving on your own before revealing the answer!

Final Answer:

Cytokinesis is the division of the cytoplasm, usually starting during telophase, and is recognized by the formation of a cleavage furrow that pinches the cell into two.

Q17. For the lab practical – be able to label the phases of mitosis from a picture of cells undergoing mitosis.

Background

Topic: Microscopy and Mitosis

This question is about visually identifying the stages of mitosis in cell images.

Key Terms:

Prophase
Metaphase
Anaphase
Telophase

Step-by-Step Guidance

Review the visual characteristics of each mitosis phase (chromosome arrangement, nuclear envelope, spindle fibers).
Practice matching images to the correct phase based on these features.
Pay attention to the position and shape of chromosomes in each phase.

Try solving on your own before revealing the answer!

Final Answer:

Each phase of mitosis has distinct visual features: prophase (condensed chromosomes), metaphase (chromosomes aligned at center), anaphase (chromatids pulled apart), telophase (chromosomes at poles, nuclear envelope reforms).

Q18. For protein synthesis, what serves as the blueprint?

Background

Topic: Protein Synthesis

This question is about the molecule that contains the instructions for building proteins.

Key Terms:

DNA
Gene

Step-by-Step Guidance

Recall which molecule stores genetic information in the cell.
Think about how this information is used to direct protein synthesis.

Try solving on your own before revealing the answer!

Final Answer:

DNA serves as the blueprint for protein synthesis.

Q19. What is a gene? What is a triplet code?

Background

Topic: Genes and Genetic Code

This question is about the basic units of heredity and how genetic information is encoded.

Key Terms:

Gene
Triplet code
Codon

Step-by-Step Guidance

Define a gene in terms of its function in the cell.
Explain what is meant by the triplet code and how it relates to amino acids.
Consider how the sequence of DNA bases determines protein structure.

Try solving on your own before revealing the answer!

Final Answer:

A gene is a segment of DNA that codes for a protein. The triplet code refers to three DNA bases (a codon) that specify one amino acid.

Q20. What is a ribosome, and what role does it have in protein synthesis?

Background

Topic: Ribosomes and Protein Synthesis

This question is about the cellular machinery responsible for assembling proteins.

Key Terms:

Ribosome
Translation

Step-by-Step Guidance

Define what a ribosome is and where it is found in the cell.
Describe the ribosome's function in the process of protein synthesis.
Consider the steps of translation and the ribosome's involvement.

Try solving on your own before revealing the answer!

Final Answer:

A ribosome is a cellular structure that assembles amino acids into proteins during translation.

Q21. What are the three types of RNA that play a role in protein synthesis? How do they assist with protein synthesis?

Background

Topic: Types of RNA

This question is about the different RNA molecules involved in making proteins and their specific roles.

Key Terms:

mRNA (messenger RNA)
tRNA (transfer RNA)
rRNA (ribosomal RNA)

Step-by-Step Guidance

List the three main types of RNA involved in protein synthesis.
Describe the function of each type in the process.
Think about how these RNAs interact during translation.

Try solving on your own before revealing the answer!

Final Answer:

mRNA carries the genetic code from DNA, tRNA brings amino acids to the ribosome, and rRNA forms part of the ribosome and helps catalyze protein synthesis.

Q22. What are the two phases of protein synthesis, and where do they occur?

Background

Topic: Protein Synthesis Phases

This question is about the two main steps in making a protein and their cellular locations.

Key Terms:

Transcription
Translation
Nucleus
Cytoplasm

Step-by-Step Guidance

Name the two phases of protein synthesis.
Identify where each phase takes place in the cell.
Briefly describe what happens in each phase.

Try solving on your own before revealing the answer!

Final Answer:

Transcription (in the nucleus) makes mRNA from DNA; translation (in the cytoplasm) assembles proteins from mRNA instructions.

Q23. Be able to take a template DNA strand and code it into RNA. For example: DNA sequence is AAT-CGT-TCG, then the mRNA corresponding codons are UUA-GCA-AGC.

Background

Topic: Transcription and Base Pairing

This question is about converting a DNA sequence into its corresponding mRNA sequence using base pairing rules.

Key Terms:

Transcription
mRNA
Base pairing

Step-by-Step Guidance

Recall the base pairing rules for transcription: A pairs with U, T with A, C with G, G with C.
Given a DNA template, write the complementary mRNA sequence using these rules.
Group the mRNA sequence into codons (sets of three bases).

Try solving on your own before revealing the answer!

Final Answer:

For DNA AAT-CGT-TCG, the mRNA codons are UUA-GCA-AGC.

Q24. What occurs during translation? Transcription?

Background

Topic: Protein Synthesis Steps

This question is about the processes that convert genetic information into proteins.

Key Terms:

Transcription
Translation
mRNA
Protein

Step-by-Step Guidance

Define what happens during transcription (DNA to mRNA).
Define what happens during translation (mRNA to protein).
Identify the cellular locations for each process.

Try solving on your own before revealing the answer!

Final Answer:

During transcription, DNA is used to make mRNA in the nucleus. During translation, mRNA is used to assemble a protein at the ribosome in the cytoplasm.