Cell Theory and Structures Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which statement best describes the function of the plasma membrane?

It produces ATP through oxidative phosphorylation.

It modifies, packages, and distributes proteins within the cell.

It controls the selective permeability of substances in and out of the cell. (correct)

It contains DNA and directs protein synthesis.

What is the primary role of the Rough Endoplasmic Reticulum?

Storing excess nutrients and products within the cell.

Synthesizing proteins due to the presence of ribosomes. (correct)

Producing lipids for membrane synthesis.

Breaking down foreign molecules using hydrolytic enzymes.

What is the main structural component of microtubules?

Irregular threadlike proteins used for rigidity.

Hollow tubes composed of tubulin proteins. (correct)

Thin filaments providing muscle contraction.

Actin chains composed of myosin.

Which organelle is responsible for detoxifying waste products in the cell?

Peroxisomes, using oxidative enzymes. Signup and view all the answers

Which statement accurately reflects the role of the nucleus in a cell?

It serves as the blueprint for cell replication and directs protein synthesis. Signup and view all the answers

What is the primary role of creatine phosphate during muscle contraction?

To enable rapid ATP production Signup and view all the answers

What is produced during the glycolysis process apart from ATP?

NADH and pyruvate Signup and view all the answers

Which component of the extracellular matrix is primarily responsible for tensile strength?

Collagen Signup and view all the answers

How does the electron transport chain generate ATP?

By pumping hydrogen ions into the intermembrane space Signup and view all the answers

Which type of cell junction is characterized as impermeable?

Tight junctions Signup and view all the answers

What is the primary function of desmosomes?

Adhering cells together for structural integrity Signup and view all the answers

What happens to pyruvate when oxygen is limited or unavailable?

It is transformed into lactate Signup and view all the answers

What is the composition of the plasma membrane primarily made of?

Lipids and proteins Signup and view all the answers

Which type of fibers allows cells to stretch and recoil?

Elastin Signup and view all the answers

What is the total ATP yield from one complete turn of the citric acid cycle?

2 ATP Signup and view all the answers

Study Notes

Principles of Cell Theory

Cell is the fundamental unit of life.
Functionality is determined by cellular structure.
All cells share similarities in structure and function.

Cell Structures & Functions

Plasma Membrane:
- Thin lipid bilayer with embedded proteins.
- Provides selective permeability to regulate substances entering and exiting the cell.
Nucleus:
- Houses DNA and is surrounded by a double membrane.
- Acts as a blueprint for cell replication and directs protein synthesis.
Endoplasmic Reticulum (ER):
- Consists of folded membranes to increase surface area.
- Rough ER: Contains ribosomes, mainly for protein production.
- Smooth ER: Involved in lipid production.
Golgi Complex:
- Stacked, flattened sacs for modifying, packaging, and distributing proteins.
Lysosomes:
- Small membranes that break down foreign molecules using hydrolytic enzymes.
Peroxisomes:
- Detoxify waste utilizing oxidative enzymes.
Centrioles:
- Pair of cylindrical structures that form microtubules for cell division and the formation of cilia and flagella.
Mitochondria:
- ATP production site with an inner membrane folded into cristae, providing a large surface area for reactions.
- Matrix is the inner cavity of mitochondria.

Cytoskeleton

Microtubules:
- Hollow tubes composed of tubulin, maintain cell shape and movement, and position organelles.
Microfilaments:
- Small chains of actin; integral in muscle contraction.
Intermediate Filaments:
- Provide stiffness and resistance to stress, made up of irregular threadlike proteins like keratin.

Cytosol

Gel-like substance within the cell.
Contains enzymes for metabolism and nutrient storage.

Cellular Metabolism

ATP produced from creatine phosphate (CP) for rapid energy during stress (like muscle contraction).
Anaerobic glycolysis converts pyruvate to lactate when oxygen is unavailable.

Respiration Process

Glycolysis:
- Breakdown of glucose in the cytosol yielding 2 pyruvate, 2 ATP, and 2 NADH.
- McArdle disease: Deficiency in enzyme converting glycogen to glucose.
Pyruvate Decarboxylation:
- Converts pyruvates into 2 Acetyl-CoA, with release of 2 CO2 and production of 2 NADH.
Citric Acid Cycle:
- Acetyl-CoA joins oxaloacetate to form citrate in 8 steps, yielding 2 ATP, 6 NADH, 2 FADH2, and 4 CO2.
- Hydrogen removal contributes to the electron transport chain.
Electron Transport Chain (ETC):
- Electrons pass through protein complexes, pumping hydrogen ions to create a gradient.
- ATP synthesis occurs as hydrogen returns through ATP synthase and electrons are combined with oxygen to form water.
- Produces approximately 32 ATP.

Plasma Membrane

Acts as a barrier between intracellular and extracellular fluids.
Composed of lipids (50%) and proteins (50%), utilizing a fluid mosaic model for flexibility.

Cell-Cell Adhesion

Cells adhere through cell adhesion molecules (CAM), enhancing intercellular connections but not providing the strongest bond.

Extracellular Matrix (ECM)

Gel-like mixture contains interstitial fluid and fibrous proteins produced by fibroblasts.
Collagen: Provides tensile strength, most abundant ECM protein.
Elastin: Offers elasticity and resilience, crucial for stretchable tissues like lungs.
Fibronectin: Promotes adhesion and stability among cells.

Specialized Cell Junctions

Desmosomes:
- Strong adhesion structures linking cells via the ECM, composed of cadherins and filaments.
Tight Junctions:
- Form impermeable barriers between cells, often found in epithelial tissues.
Gap Junctions:
- Protein tunnels (connexons) that allow communication and transport between adjacent cells.

Studying That Suits You

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

Description

Test your knowledge on the fundamental principles of cell theory and the various cell structures. This quiz covers essential concepts such as the plasma membrane, nucleus, and endoplasmic reticulum, highlighting their functions and significance. Enhance your understanding of the basic unit of life!