Cell Biology Quiz on Cytoskeleton Functions

Questions and Answers

The ______ are known as the power generating units of the cells.

mitochondria

The ______ is a network of tubular and flat vesicular structures in the cytoplasm.

endoplasmic reticulum

The ______ are membrane-enclosed sacs responsible for packaging and modifying proteins.

Golgi bodies

Lysosomes are irregular structures surrounded by a ______ membrane.

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The ______ functions in the detoxification of harmful substances and the metabolism of fatty acids.

peroxisomes Signup and view all the answers

The membrane-bound structure that contains enzymes responsible for digestion and recycling of cellular components is called a ______.

lysosome Signup and view all the answers

Peroxisomes are involved in the breakdown of fatty acids and the detoxification of ______.

hydrogen peroxide Signup and view all the answers

In eukaryotic cells, the ______ serves as a framework for the cell that helps maintain its shape and aids in cellular movement.

cytoskeleton Signup and view all the answers

The primary function of organelles in a cell is to ______ specific tasks that are vital for the cell's health and function.

perform Signup and view all the answers

The ______ function of the nucleus is to control cellular activities and store genetic information.

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Study Notes

FUNCTIONS OF CELLULAR ORGANELLES

Mitochondria serve as power-generating units, crucial for energy transduction via respiration and thermogenesis.
Mitochondria regulate calcium ion concentrations in various cell compartments.

ENDOPLASMIC RETICULUM (ER)

Composed of a network of tubular and flattened vesicular structures known as cisternae.
Contains an Endoplasmic Matrix within its tubules.
Divided into two main types:
- Smooth Endoplasmic Reticulum (SER)
  - Lacks ribosomes.
  - Synthesizes lipids and steroid hormones.
  - Predominantly found in cells involved in lipid production, such as adipocytes and adrenal cortex cells.
- Rough Endoplasmic Reticulum (RER)
  - Contains ribosomes for protein synthesis.
  - Primarily responsible for synthesizing proteins, processing, and packaging.
  - Located in protein-secreting cells, such as pancreatic acinar cells and plasma cells.
Functions include protein segregation, unsaturation of fatty acids, and muscle contraction.
Often referred to as sarcoplasmic reticulum in muscle fibers.

GOLGI BODIES

Comprised of multiple stacked layers of membrane-bound sacs adjacent to the nucleus.
Contains distinct compartments organized into four functional regions: cis Golgi network, Golgi stack, and trans Golgi network.
Function as the cell's wrapping and packaging department.
Involved in producing secretion granules that store hormones and enzymes in protein-secreting cells.
Facilitates the formation of lysosomes and adds carbohydrates to proteins, creating glycoproteins essential for tissue formation.

LYSOSOMES

Diameter ranges from 250 to 750 nm and consists of irregular structures surrounded by a membrane.
Contain enzymes for degrading cellular waste, making them crucial for cellular digestion and recycling.

CYTOSOL

The aqueous medium of the cytoplasm outside organelles, accounting for nearly 70% of total cell volume.
Composed of cytoskeleton filaments, organic molecules, salts, and water.
Contains unique proteins and chemical elements vital for cellular metabolism.

ORGANELLES

Key organelles in the cytoplasm include mitochondria, endoplasmic reticulum, lysosomes, Golgi apparatus, peroxisomes, and vacuoles.
Each organelle is enclosed by a lipid membrane and performs specific biological functions.

MITOCHONDRIA

First observed by Kolliker in 1850, recognized as the "powerhouse of the cell."
Morphology includes outer and inner membranes, an intermediate space, cristae, and an inner matrix.
Outer membrane contains porins, allowing passage for small molecules.
Inner matrix is the site for the citric acid cycle and respiratory chain oxidation processes.
Involved in ATP synthesis and metabolism of carbohydrates, lipids, and amino acids.
Contains mitochondrial DNA which encodes some mitochondrial proteins.

NUCLEUS

Houses chromatin, RNAs, and nuclear proteins in an aqueous environment.
Organizes genetic material and localizes nuclear functions via a matrix of nuclear lamins.
Chromatin is associated with lamins, facilitating structural integrity and gene regulation.

NUCLEAR ENVELOPE

Composed of two membranes and a nuclear lamina, with nuclear pore complexes facilitating transport.
Outer membrane connects with the endoplasmic reticulum, facilitating communication.
Penetrable primarily to small nonpolar molecules, providing a selective barrier.

CELLULAR FUNCTIONS

The nucleus acts as both a repository for genetic information and a control center for gene expression, allowing complex regulation mechanisms such as posttranscriptional regulation.
Each cellular compartment performs distinct metabolic functions, ensuring proper cellular operation and homeostasis.

Description

Test your understanding of the cytoskeleton, focusing on the roles and characteristics of intermediate filaments and microfilaments. This quiz covers their structure, function, and significance in cellular processes such as movement and secretion. Ideal for students studying cell biology.