Concept of Cell Structure

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the ribosomes in a cell?

To regulate the entry and exit of materials

To synthesize proteins (correct)

To store genetic material

To provide structural support

Which type of cells have a nucleus and membrane-bound organelles?

Eukaryotic cells (correct)

Prokaryotic cells

Multicellular cells

Unicellular cells

What is the main function of red blood cells?

To store genetic material

To synthesize proteins

To carry oxygen and carbon dioxide (correct)

To propagate nerve impulses

What is the structure that encloses all the organelles in a cell?

Plasma membrane Signup and view all the answers

Which type of cells are typically long and thin, with a subcellular part attached to the end?

Neurons cells Signup and view all the answers

What are the four major macromolecules found in cells?

Carbohydrates, proteins, lipids, and DNA Signup and view all the answers

What is the function of the nucleoid in prokaryotic cells?

To store genetic material Signup and view all the answers

What is the composition of the cell wall in bacteria?

Peptidoglycans Signup and view all the answers

What is the main function of the fimbriae in prokaryotic cells?

To enable the bacteria to adhere to the surface of the host cell or other bacteria Signup and view all the answers

What is the primary role of the glycocalyx in prokaryotic cells?

To protect the cell from the external environment Signup and view all the answers

What is the function of sex pili in prokaryotic cells?

To facilitate the transport of genetic material between bacteria cells Signup and view all the answers

What is the main difference between prokaryotic and eukaryotic cells?

Prokaryotic cells are smaller in size, while eukaryotic cells are larger Signup and view all the answers

What is the function of the cytoskeleton?

To provide strength, rigidity, and shape to the cell Signup and view all the answers

What is composed of ribosomal protein and ribosomal RNA (rRNA)?

Ribosomes Signup and view all the answers

What is the function of the nuclear pore?

To control the movement of molecules in and out of the nucleus Signup and view all the answers

What is the function of microtubules in eukaryotic cells?

To facilitate the movement of organelles and vesicles Signup and view all the answers

Study Notes

Cell Types

Cells can be categorized into unicellular and multicellular organisms
Bacteria, protozoa, and unicellular fungi are examples of unicellular organisms without a nucleus
Human, plants, and animals are multicellular organisms with more than one cell, containing a nucleus and plasma membrane

Characteristics of Red Blood Cells

Red blood cells are unicellular and lack a nucleus
They are typically biconcave in shape and responsible for carrying oxygen in the blood

Characteristics of Neurons

Neurons are long and thin cells responsible for propagating nerve impulses for signaling
They have subcellular parts attached to the end of the cell

Common Features of All Cells

Cells contain four major macromolecules: carbohydrates, proteins, lipids, and nucleic acids
These macromolecules are polymers formed from smaller units called monomers
All cells have a plasma membrane, cytoplasm, ribosomes, and DNA molecules

Prokaryotic Cells

Prokaryotic cells are unicellular and lack a nucleus and membrane-bound organelles
They have a simple intracellular organization and a rigid cell wall composed of peptidoglycans in bacteria
Components of prokaryotic cells include:
- Cell membrane (regulates entry and exit of materials)
- Cytoplasm (rigid gel-like substance within the cell membrane)
- Ribosomes (70S, responsible for protein synthesis)
- Nucleoid (contains genetic material, single circular bacterial DNA chromosome)
- Plasmids (small circular DNA molecule that can replicate independently)
Prokaryotic cells have protective coating layers: glycocalyx, cell wall, and cell membrane
External structures include sex pili (facilitate genetic material transport), fimbriae (enable bacteria to adhere to surfaces), and flagella (used for locomotion)

Eukaryotic Cells

Eukaryotic cells are multicellular and contain a nucleus and membrane-bound organelles
They have a simple intracellular organization and are larger in size compared to prokaryotic cells
Components of eukaryotic cells include:
- Cell membrane
- Cytoplasm (occupies everything outside the nucleus, including cytosol, microtubules, and other organelles)
- Ribosomes (80S, composed of ribosomal protein and rRNA)
- Lysosomes (only in animal eukaryotic cells)
- Chloroplasts (only in plant cells, responsible for photosynthesis)
- Peroxisome
- Nucleolus (chromatin)
- Nuclear membranes
- Nuclear pore
- Smooth and rough endoplasmic reticulum
- Mitochondria
- Golgi apparatus
- Centrioles

Cytoskeleton

The cytoskeleton is a three-dimensional structure of protein in the cytoplasm
It regulates cell shape and orientation, providing strength and rigidity, and facilitates organelle movement and cellular processes
The cytoskeleton is composed of three filamentous protein polymers: microfilaments, intermediate filaments, and microtubules
These protein filamentous polymers are involved in muscle contraction, cell signaling, and other cellular processes

Studying That Suits You

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

Description

Understand the differences between unicellular and multicellular organisms, including their characteristics and components. Learn about the nucleus, plasma membrane, and organelles that make up a cell.