Mitochondrial Functions and Cell Biology Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What occurs during the G1 phase of interphase?

Synthesis of macromolecules essential for DNA duplication begins. (correct)

DNA duplication takes place.

The cell divides its nucleus and cytoplasm.

Preparation for mitosis begins.

Which of the following statements is true regarding somatic cells?

They undergo meiosis for reproduction.

They do not utilize mitosis at any point.

They use mitosis for cell division. (correct)

They are always in a stable phase.

What is the function of nucleostemin in relation to cellular components?

It coexists with granular components but is unrelated to ribosomal biogenesis. (correct)

It aids in ribosomal biogenesis.

It exclusively functions in the G0 phase.

It cooperates with cytoskeletal elements.

During which phase does the replication of chromatin into discrete chromosomes occur?

Prophase Signup and view all the answers

Which type of cells are said to be in a terminally differentiated G0 state?

Neurons and skeletal muscle cells Signup and view all the answers

What structures in the mitochondria are responsible for increasing its surface area?

Cristae Signup and view all the answers

Which enzyme complex allows protons to flow back into the mitochondrial matrix?

ATP synthase Signup and view all the answers

What is a major source of electrons for the electron-transport chain?

NADH Signup and view all the answers

What evidence supports the endosymbiotic theory regarding mitochondria?

Mitochondria have their own round DNA. Signup and view all the answers

What is formed as a byproduct of fatty acid catabolism in peroxisomes?

Hydrogen peroxide Signup and view all the answers

What molecule is primarily converted to acetyl CoA in mitochondria during the Krebs cycle?

Pyruvate Signup and view all the answers

Which process is not performed by peroxisomes?

Production of ATP Signup and view all the answers

What is the function of the electrochemical gradient in mitochondria?

To promote ATP synthesis Signup and view all the answers

What are the components of a prokaryotic ribosome?

50S subunit and 30S subunit Signup and view all the answers

Which protein is responsible for transporting vesicles towards the positive end of the cytoskeleton?

Kinesin Signup and view all the answers

How does the stiffness of the substrate affect cell differentiation?

Softer substrates promote the expression of brain cell genes. Signup and view all the answers

What is the role of blebbistatin in cell differentiation studies?

Blocks cell contraction, preventing matrix assessment. Signup and view all the answers

Integrins are primarily involved in which function within the cell?

Cell adhesion and substrate binding Signup and view all the answers

What are the three approaches to tissue engineering?

Using a matrix, drugs, and cell implantation Signup and view all the answers

What distinguishes eukaryotic ribosomes from prokaryotic ribosomes?

Eukaryotic ribosomes have different subunit sizes. Signup and view all the answers

Which cell shape is associated with the differentiation into osteoblasts?

Star shape Signup and view all the answers

What is the primary function of the Golgi apparatus?

Post translational modification of proteins Signup and view all the answers

Where does the packing of RER content into vesicles primarily occur?

Golgi apparatus Signup and view all the answers

What is the role of lysosomes in cellular function?

Digest bacteria and cellular debris Signup and view all the answers

What characteristic of epithelial cells specialized for secretion is noted in their polarity?

RER is abundant at the basal ends Signup and view all the answers

Which compartment is located between RER and the cis-face of the Golgi apparatus?

Vesicular-tubular clusters (VTCs) Signup and view all the answers

What is a key function of mitochondria in cells?

Act as sensors of cellular health Signup and view all the answers

What type of environment is required for lysosomal enzymes to be active?

Acidic pH Signup and view all the answers

Which of the following does not define the structure of the Golgi apparatus?

Presence of ribosomes Signup and view all the answers

Which process involves the cell membrane engulfing particles like bacteria?

Phagocytosis Signup and view all the answers

What is the primary function of coated vesicles in endocytosis?

To mediate the internalization of ligands when receptors are bound Signup and view all the answers

How does receptor-mediated endocytosis differ from regular endocytosis?

It requires specific binding of receptors to ligands. Signup and view all the answers

What happens to the vesicle after exocytosis takes place?

It releases materials outside the cell and adds to the cell membrane. Signup and view all the answers

What is the initial action of the cell membrane during pinocytosis?

Invaginating to form a pit. Signup and view all the answers

During cell signaling, what role does the vesicle play when it contains the ligand-receptor complex?

It continues to emit signals within the cell. Signup and view all the answers

Which of the following best describes phagocytosis?

The engulfing of large particles. Signup and view all the answers

What happens to the cell membrane during the receptor-mediated endocytosis process?

It forms a new membrane component after vesicle fusion. Signup and view all the answers

What role does the rough endoplasmic reticulum (RER) primarily serve in the cell?

Production and secretion of proteins Signup and view all the answers

Which of the following correctly describes the smooth endoplasmic reticulum (SER)?

It plays a key role in the synthesis of cholesterol. Signup and view all the answers

How do ribosomes aid in the process of protein synthesis?

They move along the mRNA to decode genetic information. Signup and view all the answers

What function does the endoplasmic reticulum lumen serve in the cell?

Storage of lipid droplets Signup and view all the answers

In which type of cells is the smooth endoplasmic reticulum (SER) particularly well-developed for muscle contraction?

Striated muscle cells Signup and view all the answers

What type of cells typically have a high presence of free ribosomes in the cytoplasm?

Erythroblasts producing hemoglobin Signup and view all the answers

What is one of the key roles of the endoplasmic reticulum in relation to mitochondria?

To synthesize phospholipids Signup and view all the answers

Which statement correctly describes the staining characteristic of the cytoplasm in cells with abundant RER?

It stains pink because it is eosinophilic. Signup and view all the answers

Signup and view all the answers

What is the primary function of phagocytosis?

To internalize large particles such as bacteria Signup and view all the answers

Which process involves the invagination of the cell membrane to form a vesicle containing extracellular fluid?

Pinocytosis Signup and view all the answers

What activates the formation of coated vesicles during receptor-mediated endocytosis?

The binding of the ligand to its receptor Signup and view all the answers

During which process does the cell membrane fuse with a vesicle to release its contents outside the cell?

Exocytosis Signup and view all the answers

Which type of vesicle is typically involved in the signaling process inside a cell after endocytosis?

Endocytic vesicle Signup and view all the answers

How do receptor-mediated endocytosis and regular endocytosis differ?

Receptor-mediated endocytosis uses ligands for internalization, while regular does not Signup and view all the answers

Which protein is commonly associated with coated vesicles involved in the endocytic process?

Clathrin Signup and view all the answers

What occurs to the ligands after they are internalized in receptor-mediated endocytosis?

They continuously bind to their receptors inside the vesicle Signup and view all the answers

What distinguishes the rough endoplasmic reticulum (RER) from the smooth endoplasmic reticulum (SER)?

RER has ribosomes on its surface, while SER does not. Signup and view all the answers

Which subunit of the ribosome is responsible for the exit of the polypeptide chain during translation?

E site Signup and view all the answers

What role does the smooth endoplasmic reticulum (SER) play in muscle cells?

Calcium sequestration and release. Signup and view all the answers

How does the rough endoplasmic reticulum (RER) differ in cells that primarily produce hemoglobin?

It has a high amount of ribosomes. Signup and view all the answers

What is the primary function of the endoplasmic reticulum lumen?

Lipid droplet storage. Signup and view all the answers

Which enzyme is involved in the detoxification of harmful exogenous molecules in the smooth endoplasmic reticulum?

Cytochrome P450. Signup and view all the answers

What characterizes the appearance of the cytoplasm in cells abundant with rough endoplasmic reticulum when stained with H&E?

It turns pink, reflecting eosinophilia. Signup and view all the answers

In which type of cell is the smooth endoplasmic reticulum (SER) especially well developed for its role in contraction?

Striated muscle cell. Signup and view all the answers

What is the primary function of lipid droplets in cells?

They store lipids and actively transport them within the cell. Signup and view all the answers

What is true about glycogen granules?

They are aggregates of glycogen used as a quick energy source. Signup and view all the answers

What is the condition called when a cell has one set of chromosomes?

Haploid Signup and view all the answers

Which statement accurately describes necrosis?

The cell's plasma membrane bursts, releasing internal molecules. Signup and view all the answers

Which function best describes the role of exportins?

They export macromolecules from the nucleus to the cytoplasm. Signup and view all the answers

What aspect distinguishes sex chromosomes from autosomes?

Their role in determining biological sex Signup and view all the answers

Which of the following accurately describes a Barr body?

A silenced X chromosome in females Signup and view all the answers

What is one of the controlling mechanisms of apoptosis?

Release of caspase-activating enzymes. Signup and view all the answers

Which type of epithelial tissue is responsible for forming glands that secrete substances?

Secretory/glandular epithelia Signup and view all the answers

What is the significance of pigment deposits like melanin granules in cells?

They protect cell nuclei from DNA damage caused by light. Signup and view all the answers

What is the main function of the nucleolus within the cell's nucleus?

To produce and assemble ribosomes Signup and view all the answers

What is a primary characteristic of epithelial tissue compared to connective tissue?

Epithelial cells have sides and are polarized. Signup and view all the answers

How many pairs of autosomes does a normal human karyotype have?

22 Signup and view all the answers

What is the primary structure surrounding the nucleus?

Nuclear envelope composed of two membranes. Signup and view all the answers

What is the role of the basement membrane for epithelial cells?

It connects epithelium to connective tissue. Signup and view all the answers

Which component facilitates the bidirectional traffic between the nucleus and the cytoplasm?

Nuclear localization signals and transport proteins. Signup and view all the answers

Which component of the basement membrane allows epithelial cells to connect to their environment?

Laminin Signup and view all the answers

What happens to telomeres with each cell division?

They shorten indicating the cell is aging Signup and view all the answers

What is the primary function of the apical domain of epithelial cells?

Displays specialized features to interact with the lumen or external environment Signup and view all the answers

What term describes the display of an organism's complete set of chromosomes?

Karyotype Signup and view all the answers

Which component of the nucleolus is primarily involved in the assembly of ribosomal subunits?

Granular component Signup and view all the answers

In contrast to epithelial tissue, which type of tissue does not have polarized cells?

Connective tissue Signup and view all the answers

Which connective tissue component is essential for the mechanical stability of epithelial tissues?

Basement membrane Signup and view all the answers

What is the primary function of connective tissue in relation to other tissues?

To provide support and protection Signup and view all the answers

During which phase do sister chromatids separate and move towards opposite spindle poles?

Anaphase Signup and view all the answers

What primarily causes the asymmetrical division of stem cells?

Extracellular environment Signup and view all the answers

What structural component forms a cleavage furrow during cytokinesis?

Actin filaments and myosin Signup and view all the answers

What do kinetochores attach to during metaphase?

Centromere DNA Signup and view all the answers

What is the primary role of stem cells in tissues?

To differentiate into specialized cells Signup and view all the answers

What occurs to the nuclear envelope during telophase?

It reassembles around daughter chromosomes Signup and view all the answers

What describes the primary difference between stem cells and progenitor cells?

Stem cells can divide indefinitely, progenitor cells cannot. Signup and view all the answers

Which phase of mitosis is characterized by the further condensation of chromosomes?

Metaphase Signup and view all the answers

Study Notes

Histology

Histology is the study of the microscopic structure of normal tissues, enabling understanding of tissue function.
Tissues are organized collections of cells with similar morphology (epithelial, muscular, nervous, connective).
Cell size ranges from 10-30 micrometers.
Microscopes are used to observe cells.

Light Transmission Microscopy

Uses visible light passing through a sample.
Objective lenses magnify and project the image to the eyepiece.
Magnifications range from X40 to X400.
Samples must be transparent.
Tissue sections are prepared for viewing.

Tissue Preparation

Fixation: Preserves tissue structure by cross-linking proteins and inactivating enzymes.
Dehydration: Removing water using increasingly concentrated alcohol solutions (65% to 100%).
Clearing: Replacing alcohol with an organic solvent (e.g., paraffin).
Infiltration: Embedding tissue in melted paraffin wax.
Embedding: Hardening the paraffin-infiltrated tissue in a mold.
Trimming: Preparing the paraffin block for sectioning on a microtome.

Staining

Sections are stained to visualize structures and substances.
Hematoxylin and eosin (H&E) stain is commonly used.
Cell nuclei stain blue, while most cytoplasm stains pink/red.
PAS (periodic acid-Schiff) stains carbohydrates, either alone or with other molecules.

Immunochemistry

Uses antibodies to target specific molecules (e.g., proteins) of interest.
Antibodies bind to target antigens, allowing identification & visualization.

Microscopy Techniques

Phase-contrast microscopy: Useful for observing unstained specimens.
Confocal microscopy: Images one precise slice of the sample.
Stereomicroscopy: Used to observe 3D, non-transparent objects.
Super-resolution microscopy: STORM, STED, high-resolution images.

Electron Microscopy

Transmission electron microscopy (TEM): 2D images of thin sections.
Scanning electron microscopy (SEM): 3D images of surfaces.

The Cell

The plasma membrane is a double layer of phospholipids with cholesterol and proteins.
Cholesterol affects the fluidity and flexibility.
Proteins facilitate recognition, signaling, and transport across the membrane.
Glycosidic chains are present on phospholipids and proteins (glycolipids and glycoproteins).
Hyaluronic acid creates a jelly-like layer outside the cell, providing cushioning and lubrication.

Membrane Transport

Simple diffusion: Lipophilic and small uncharged molecules cross membranes passively.
Channel/facilitated diffusion: Membrane proteins allow passage of specific chemicals.
Active transport (pumps): Moves molecules against concentration gradients.

Cytoskeleton

Microtubules: Hollow tubes formed by tubulin; crucial for cell division, intracellular transport, and structure.
Microfilaments: Two strands of actin; important in cell movements, structure, and cell contraction.
Intermediate filaments: Structural support for cells.

Organelles

Ribosomes: Sites of protein synthesis.
Endoplasmic reticulum (ER): Synthesis and modification of proteins; lipid metabolism.
Golgi apparatus: Processing, sorting, and modifying proteins and lipids.
Lysosomes: Contain enzymes for digestion/waste removal.
Mitochondria: Energy production (ATP) through cellular respiration.
Peroxisomes: Involved in oxidation reactions.

Cellular Inclusion

Lipid droplets: Store lipids in cells.
Glycogen granules: Store glycogen (energy).
Pigment deposits: Protect cell nuclei (e.g., melanin).
Hemosiderin granules: Store iron.

Cell Death

Necrosis: Cell swelling and rupture; causes inflammation.
Apoptosis: Programmed cell death, not inflammatory.

The Nucleus

The nucleus is a double membrane-bound structure containing the cell's DNA.
Pores regulate traffic between the nucleus and the cytoplasm.
Chromatin (DNA complexed with histones) is organized into nucleosomes.
Chromosomes condense during cell division.
The nucleolus is the site of ribosome assembly.

Cell Cycle

The cell cycle consists of interphase (G1, S, G2) and the mitotic phase (mitosis and cytokinesis).
Cell cycle checkpoints are critical for regulated cell growth and division.

Tissues

Tissues are organized groups of similar cells working together.
Epithelial tissues: Cover body surfaces, line cavities, and form glands.
Connective tissues: Provide support, structure, and connect tissues.
Muscle tissues: Responsible for movement.
Nervous tissues: Transmit electrical signals.

Types of Epithelia

Covering/lining epithelia: Classified by cell shape (squamous, cuboidal, columnar) and layering (simple, stratified).
Glandular epithelia: Specialized for secretion; unicellular (e.g., goblet cells) or multicellular (e.g., salivary glands, pancreas).

Specializations of Epithelial Cells

Microvilli: Increase surface area for absorption.
Stereocilia: Increase surface area (e.g., in the inner ear).
Cilia: Movement of substances (e.g., in the respiratory tract).
Cell-to-cell junctions (tight junctions, adherens junctions, desmosomes, gap junctions): attach, communicate, or block substances from passing between cells.

Connective Tissues

Connective tissues have a matrix that contains ground substance (GAGs, proteoglycans, proteins) and fibers (collagen, elastic).
Loose connective tissues: Support and connect tissues (e.g., lamina propria).
Dense connective tissues: Support and provide strength and structure (e.g., tendons, ligaments).
Cartilage: Tough, flexible support (hyaline, elastic, fibrocartilage).
Bone: Hard, mineralized support (spongy, compact).

Specialised Cells

Fibroblast: Maintain and synthesize collagen fibers.
Macrophages: Phagocytic cells.
Mast cells: Release histamine/heparin in inflammation.
Lymphocytes(B-lymphocytes and T-lymphocytes): part of the immune system.
Plasma cells: Antibody production.
Osteoblasts: Produce bone matrix.
Osteocytes: Maintain bone matrix.
Osteoclasts: Resorb bone matrix.

Bone Remodeling

A cyclical process of bone resorption and formation, important for maintaining bone calcium levels and adapting to stress.
Involved in many physiological processes including fracture healing.

Types of Gland

Exocrine Glands: Secrete products into ducts that empty onto epithelial surfaces (e.g., Sweat glands, salivary glands, goblet cells).
Endocrine Glands: Secrete hormones directly into blood (e.g., Thyroid gland, adrenal glands, pancreas).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on mitochondrial functions, the phases of the cell cycle, and cellular components. This quiz covers essential concepts related to interphase, somatic cells, and the endosymbiotic theory, among others. Perfect for students studying cell biology and biochemistry.