Eukaryotic cells are characterized by having a true nucleus.
The nuclear material is enclosed by a membranous nuclear envelope.
Eukaryotic cells contain various membrane-bound organelles.
Organisms like animals and plants are classified as eukaryotic.
Shape:
Plant cells usually have a more rectangular or squared-off shape due to the presence of a cell wall.
Animal cells do not have a cell wall and thus can be more irregularly shaped.
Both cell types have a cell membrane but differ in the presence of a cell wall in plants.
Nucleus:
The most noticeable organelle in eukaryotic cells, typically visible under a microscope.
Contains the majority of the cell's DNA.
Enclosed by a double membrane called the nuclear envelope, which has pores for transport.
Ribosomes:
Composed of ribosomal RNA and proteins; involved in protein synthesis.
Can be free in cytosol or bound to the endoplasmic reticulum (ER) or nuclear envelope.
Not membrane-bound, so they are not classified as true organelles.
Structure:
A network of membranous tubules and sacs called cisternae.
Types of ER:
Rough ER:
Studded with ribosomes; synthesizes secretory proteins (e.g., hormones, enzymes) and membrane proteins.
Smooth ER:
Lacks ribosomes; responsible for lipid synthesis, carbohydrate metabolism, detoxification, and calcium storage.
Functions as a transport warehouse for products from the rough ER.
Modifies proteins and synthesizes carbohydrates before releasing them inside or outside the cell via vesicles.
Known as the digestive compartments of the cell, containing hydrolytic enzymes.
Responsible for digesting macromolecules into smaller parts for cellular use.
Involved in:
Phagocytosis: Engulfing external particles.
Autophagy: Recycling damaged cellular components.
Membrane-lined spaces in the cell filled with fluid, serving various functions:
Food Vacuoles: Formed by phagocytosis.
Contractile Vacuoles: Expel excess water to maintain ion concentration.
Central Vacuole (in plants): Contains cell sap, playing a role in growth and storage.
Often referred to as the powerhouse of the cell; site of cellular respiration.
Number per cell varies widely (1 to thousands) depending on the type of cell.
Mobile organelles that provide energy for cellular functions.
Convert light energy into chemical energy through photosynthesis.
Found in leaves and green parts of plants; smaller than mitochondria.
A network of fibers that extends throughout the cytoplasm, providing mechanical support and playing a role in cell movement.
Cerebellar Ataxia: A degenerative disease affecting the nervous system, characterized by:
Slurred speech, stumbling, poor coordination.
Involves progressive loss of cerebellar brain matter.
Mutation identified in gene SEL1L linked to protein packaging failure, leading to cell death.
Research may lead to targeted drugs to alleviate symptoms and slow progression.
Match Organelles with Functions:
A: Mitochondria & Photosynthesis - Incorrect (they are involved in cellular respiration).
B: Central Vacuole & Storage - Correct (contains cell sap and aids in plant growth).
C: Ribosomes & Lipid Manufacture - Incorrect (this occurs in the smooth ER).
D: Nucleus & Cellular Respiration - Incorrect (occurs in mitochondria).
E: Lysosomes & Movement - Incorrect (involved in digestion).
2.2 Eukaryotic Cell Structure
Eukaryotic cells are characterized by having a true nucleus.
The nuclear material is enclosed by a membranous nuclear envelope.
Eukaryotic cells contain various membrane-bound organelles.
Organisms like animals and plants are classified as eukaryotic.
Shape:
Plant cells usually have a more rectangular or squared-off shape due to the presence of a cell wall.
Animal cells do not have a cell wall and thus can be more irregularly shaped.
Both cell types have a cell membrane but differ in the presence of a cell wall in plants.
Nucleus:
The most noticeable organelle in eukaryotic cells, typically visible under a microscope.
Contains the majority of the cell's DNA.
Enclosed by a double membrane called the nuclear envelope, which has pores for transport.
Ribosomes:
Composed of ribosomal RNA and proteins; involved in protein synthesis.
Can be free in cytosol or bound to the endoplasmic reticulum (ER) or nuclear envelope.
Not membrane-bound, so they are not classified as true organelles.
Structure:
A network of membranous tubules and sacs called cisternae.
Types of ER:
Rough ER:
Studded with ribosomes; synthesizes secretory proteins (e.g., hormones, enzymes) and membrane proteins.
Smooth ER:
Lacks ribosomes; responsible for lipid synthesis, carbohydrate metabolism, detoxification, and calcium storage.
Functions as a transport warehouse for products from the rough ER.
Modifies proteins and synthesizes carbohydrates before releasing them inside or outside the cell via vesicles.
Known as the digestive compartments of the cell, containing hydrolytic enzymes.
Responsible for digesting macromolecules into smaller parts for cellular use.
Involved in:
Phagocytosis: Engulfing external particles.
Autophagy: Recycling damaged cellular components.
Membrane-lined spaces in the cell filled with fluid, serving various functions:
Food Vacuoles: Formed by phagocytosis.
Contractile Vacuoles: Expel excess water to maintain ion concentration.
Central Vacuole (in plants): Contains cell sap, playing a role in growth and storage.
Often referred to as the powerhouse of the cell; site of cellular respiration.
Number per cell varies widely (1 to thousands) depending on the type of cell.
Mobile organelles that provide energy for cellular functions.
Convert light energy into chemical energy through photosynthesis.
Found in leaves and green parts of plants; smaller than mitochondria.
A network of fibers that extends throughout the cytoplasm, providing mechanical support and playing a role in cell movement.
Cerebellar Ataxia: A degenerative disease affecting the nervous system, characterized by:
Slurred speech, stumbling, poor coordination.
Involves progressive loss of cerebellar brain matter.
Mutation identified in gene SEL1L linked to protein packaging failure, leading to cell death.
Research may lead to targeted drugs to alleviate symptoms and slow progression.
Match Organelles with Functions:
A: Mitochondria & Photosynthesis - Incorrect (they are involved in cellular respiration).
B: Central Vacuole & Storage - Correct (contains cell sap and aids in plant growth).
C: Ribosomes & Lipid Manufacture - Incorrect (this occurs in the smooth ER).
D: Nucleus & Cellular Respiration - Incorrect (occurs in mitochondria).
E: Lysosomes & Movement - Incorrect (involved in digestion).