Podcast
Questions and Answers
Which cellular component is primarily responsible for regulating the movement of substances in and out of the cell?
Which cellular component is primarily responsible for regulating the movement of substances in and out of the cell?
What structure can be found in bacterial cells that is not present in all eukaryotic cells?
What structure can be found in bacterial cells that is not present in all eukaryotic cells?
Which of the following components is NOT directly involved in the synthesis or modification of proteins?
Which of the following components is NOT directly involved in the synthesis or modification of proteins?
In eukaryotic cells, which structure is responsible for producing energy through aerobic respiration?
In eukaryotic cells, which structure is responsible for producing energy through aerobic respiration?
Signup and view all the answers
Which component is mainly involved in maintaining the structural integrity and rigidity of a plant cell?
Which component is mainly involved in maintaining the structural integrity and rigidity of a plant cell?
Signup and view all the answers
What is the size of the smallest human cell, the sperm cell?
What is the size of the smallest human cell, the sperm cell?
Signup and view all the answers
Which cell type is specifically designed for conducting impulses?
Which cell type is specifically designed for conducting impulses?
Signup and view all the answers
What is the term used to refer to the detailed structure of a cell as seen under an electron microscope?
What is the term used to refer to the detailed structure of a cell as seen under an electron microscope?
Signup and view all the answers
Which type of microscope allows for a magnification of up to 500000X?
Which type of microscope allows for a magnification of up to 500000X?
Signup and view all the answers
Human red blood cells are specifically adapted with what shape for their function?
Human red blood cells are specifically adapted with what shape for their function?
Signup and view all the answers
Which organelle is responsible for energy production in animal cells?
Which organelle is responsible for energy production in animal cells?
Signup and view all the answers
Which of the following statements about white blood cells is true?
Which of the following statements about white blood cells is true?
Signup and view all the answers
What is the primary structure that differentiates plant cells from animal cells?
What is the primary structure that differentiates plant cells from animal cells?
Signup and view all the answers
What defines a unicellular organism?
What defines a unicellular organism?
Signup and view all the answers
Which of the following statements is part of the cell theory?
Which of the following statements is part of the cell theory?
Signup and view all the answers
Who was the first to observe living cells?
Who was the first to observe living cells?
Signup and view all the answers
What is the smallest known type of cell and its approximate size?
What is the smallest known type of cell and its approximate size?
Signup and view all the answers
Which of the following is NOT considered a multicellular organism?
Which of the following is NOT considered a multicellular organism?
Signup and view all the answers
What was discovered by Robert Hooke in 1665?
What was discovered by Robert Hooke in 1665?
Signup and view all the answers
What unit is commonly used to measure the size of cells?
What unit is commonly used to measure the size of cells?
Signup and view all the answers
Which of the following organisms is classified as a multicellular organism?
Which of the following organisms is classified as a multicellular organism?
Signup and view all the answers
Which component of the cell is responsible for regulating the entry and exit of substances?
Which component of the cell is responsible for regulating the entry and exit of substances?
Signup and view all the answers
What is the main role of ribonucleic acid (RNA) in the cell?
What is the main role of ribonucleic acid (RNA) in the cell?
Signup and view all the answers
Which organelle is primarily involved in detoxifying drugs and poisons in liver cells?
Which organelle is primarily involved in detoxifying drugs and poisons in liver cells?
Signup and view all the answers
During cell division, what structural components help in the movement of chromosomes?
During cell division, what structural components help in the movement of chromosomes?
Signup and view all the answers
What type of cellular structure serves as the main site of energy production?
What type of cellular structure serves as the main site of energy production?
Signup and view all the answers
Which of the following is true about vacuoles in plant cells compared to those in animal cells?
Which of the following is true about vacuoles in plant cells compared to those in animal cells?
Signup and view all the answers
What structural component allows for the synthesis of lipids in the cell?
What structural component allows for the synthesis of lipids in the cell?
Signup and view all the answers
What is the relationship between chromatin and chromosomes during cell division?
What is the relationship between chromatin and chromosomes during cell division?
Signup and view all the answers
Which part of the nucleus is responsible for synthesizing ribonucleic acid (RNA)?
Which part of the nucleus is responsible for synthesizing ribonucleic acid (RNA)?
Signup and view all the answers
What role do microtubules play in the cytoskeleton?
What role do microtubules play in the cytoskeleton?
Signup and view all the answers
What is true about the centrosome?
What is true about the centrosome?
Signup and view all the answers
Which organelle is responsible for modifying, sorting, and packaging cellular materials?
Which organelle is responsible for modifying, sorting, and packaging cellular materials?
Signup and view all the answers
What primarily composes the cytoplasm?
What primarily composes the cytoplasm?
Signup and view all the answers
What is the primary function of lysosomes in a cell?
What is the primary function of lysosomes in a cell?
Signup and view all the answers
Study Notes
Introduction to Cell Structure and Function
- Cell: Basic structural and functional unit of living organisms.
- Cells: Make up living things and carry out activities that keep a living thing alive.
-
Cell Theory: Collection of ideas and conclusions from scientists about cells and their operation.
- All known living things are made up of one or more cells.
- All living cells arise from pre-existing cells by division.
- The cell is the basic unit of structure and function in all living organisms.
-
Cell Theory Timeline:
- 1665: Robert Hooke discovered cells.
- 1674: Anton Van Leeuwenhoek observed living cells.
- 1883: Robert Brown discovered the nucleus.
Unicellular and Multicellular Organisms
- Unicellular organism: An organism made up of only one cell (e.g., Euglena, Paramecium, Yeast).
- Multicellular organisms: An organism made up of more than one cell (e.g., Plants, Animals, Fungi).
Cell Size
- Cell size variation: Cells vary significantly in size.
- Microscopic cells: Most cells are microscopic (very small).
- Macroscopic cells: Some cells can be very large.
-
Micrometer (µm): Unit used to measure cell size (1 µm = 1/1000 millimeter).
- Smallest cell: Mycoplasma (0.1 µm).
- Largest cell: Ostrich egg (18 cm).
-
Human cell sizes:
- Smallest: Sperm cell (5 µm).
- Largest: Ovum cell (120 µm).
- Longest: Nerve cell (1 m).
Cell Shape
- Cell shape variation: Cells vary in shape, depending mainly on their function.
- Fixed shape: Most cells have a fixed shape.
- Changing shape: Some cells (e.g., Euglena, Amoeba) can change their shape.
- Human RBCs: Circular, biconcave shape for easy passage through capillaries.
- Human WBCs: Change shape to engulf microorganisms that enter the body.
- Nerve cells: Branched to conduct impulses from one point to another.
Cell Structure
- Compound microscope: Used to study cell structure (magnification 2000X).
- Electron microscope: Used to see the detailed structure of cells (ultrastructure) (magnification 500000X).
- Ultrastructure: Detailed structure of a cell as seen under an electron microscope.
Animal Cell Structure
- Nucleus: Contains DNA, controls cellular activities
- Golgi body: Modifies, sorts, and packages synthesized materials
- Vesicle: Small sac containing cell components
- Plasma membrane: Boundary of the cell, controls what enters/leaves
- Mitochondria: Produces energy (ATP) for the cell
- Cytoskeleton: Provides structure and support to the cell
- Cytoplasm: Jelly-like material containing organelles
- Centrioles: Help in cell division
- Lysosome: Contains enzymes to break down waste materials
- Rough ER: Involved in protein synthesis
- Smooth ER: Involved in lipid synthesis
- Nucleolus: Creates ribosomes
Plant Cell Structure
- Vacuole: Storage area for water and other materials
- Cell wall: Rigid outer layer providing support
- Chloroplasts: Site of photosynthesis
- Other structures similar to animal cells: Nucleus, Golgi body, Mitochondria, Plasma membrane, ER, Lysosomes, Cytoplasm
Bacterial Cell Structure
- Capsule, Cell wall, Plasma membrane, Cytoplasm, Flagellum, Food granules , Plasmid (DNA), Ribosomes, Nucleoid, Pili
Parts of a Cell
- Plasma membrane Semi-permeable barrier, regulates substances
- Nucleus: Contains DNA, controls cell function
-
Cytoplasm: Contains organelles and cytosol
-
Cell Organelles:
- Endoplasmic reticulum (rough and smooth)
- Rough ER: Protein synthesis
- Smooth ER: Lipid synthesis
- Golgi body: Modifies and packages proteins
- Lysosomes: Break down cellular wastes
- Vacuoles: Store substances, maintain pressure
- Mitochondria: Generates energy (ATP)
- Centrosome: Involved in cell division
- Cytoskeleton: Provides structure and support
- Endoplasmic reticulum (rough and smooth)
-
Cell Organelles:
Plasma Membrane
- Structure: Extremely delicate, thin, elastic, living; semi-permeable membrane; made of two layers lipid molecules; protein molecules are floating
- Thickness: Ranges from 75-110 Å
- Observation: Can be observed only under an electron microscope.
- Functions: Maintains shape and size; protects internal contents; regulates entry/exit of substances; maintains homeostasis.
Nucleus
- Structure: Dense spherical body located near the cell center
- Size: Diameter varies from 10-25 μm
- Presence: Present in all cells except red blood and sieve tube cells. Well-developed in plant and animal cells; undeveloped in bacteria and blue-green algae.
- Nucleolus: Creates ribosomes
- Nucleoplasm: Colourless dense sap present inside nucleus
- Chromatin: Network of chromatin fibers
- Chromosomes: DNA strands that condense during cell division
Nucleus (Continued)
- Function: Controls all cell activities (metabolism, protein synthesis, growth, cell division), stores hereditary information in genes.
Cytoplasm
- Structure: Jelly-like material (80% water) between plasma membrane and nucleus; contains cytosol, various particles (proteins, carbohydrates, nucleic acids, lipids, inorganic ions); organelles with distinct structure and function.
- Observation: Some organelles are visible only under electron microscope; granular and dense in animal cells, thin in plant cells.
Endoplasmic Reticulum (ER)
- Structure: Network of tubular and vesicular structures, with connections to nuclear and cell membranes; smooth ER and rough ER
- Rough ER: Possesses ribosomes, involved in protein synthesis.
- Smooth ER: Lacks ribosomes, involved in lipid synthesis, detoxification, and calcium storage.
- Functions: Maintain cell shape and provide support to cytoplasm, protein and membrane protein synthesization, SER detoxification of drugs and poisons, Calcium storage in muscle cells.
Golgi Body
- Structure: Flattened sacs (cisternae), with cis and trans faces; interconnected with endoplasmic reticulum and plasma membrane
- Function: Modifies, sorts, packs materials (synthesized in the cell) ; Delivers materials within and outside cell , Produces vacuoles and secretory vesicles; forms plasma membrane and lysosomes.
Lysosomes
- Structure: Small, spherical membrane sacs; contain hydrolytic enzymes
- Function: Digest large molecules, protect from foreign invaders (bacteria, viruses), degrade worn-out organelles in dead cells (perform autolysis).
Vacuoles
- Structure: Membrane-bound sacs, temporary and small in animal cells, larger and more numerous in plant cells; may be contractile or non-contractile
- Function: Store substances (including waste products), maintain osmotic pressure of the cell, store food particles in amoeba cells, provide rigidity to plant cells.
Mitochondria
- Structure: Small, rod-shaped organelles with two membranes (inner and outer), inner membrane folded into cristae; inner cavity filled with matrix
- Function: Synthesize energy-rich compound ATP, ATP provides energy for vital activities of living cells.
Mitochondrial Disease
- Description: Failure of mitochondria, parts of the cell involved with producing energy. Affects various systems (brain, heart, liver, skeletal muscles, kidney, endocrine, and respiratory). Inherited or a result of a buildup from mutations in DNA.
- Effects: Damage to cells. Can cause problems with growth, muscle movement, swallowing, processing of nutrients and other systems.
Centrosome
- Description: Membrane-bound organelle present near the nucleus; consists of two centrioles (hollow structures made of microtubules).
- Function: Form spindle fibers for chromosome movement during cell division; help in formation of cilia and flagella.
Cytoskeleton
- Description: Network of protein filaments (microtubules and microfilaments; microtubules made of tubulin, and microfilaments made of actin).
- Function: Determine cell shape, give structural strength, and contribute to cell movements.
Prokaryotic vs. Eukaryotic Cells
- Prokaryotic Cells: Nucleus is not developed, single chromosome; lack membrane-bound organelles; size range is 0.5-5 μm (examples:bacteria).
- Eukaryotic Cells: Nucleus is well-developed, multiple chromosomes ; membrane-bound organelles present; size range is 5-100 μm (examples: animals, plants, fungi).
Animal Cell vs. Plant Cell
- Animal Cell (differences from plant cell): Generally smaller, no cell wall, no plastids, vacuoles are smaller and fewer, centrioles are present.
- Plant Cell (differences from animal cell): Generally larger, has a cell wall, has plastids, vacuoles are larger and more, centrioles are absent.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fundamental concepts of cell structure and function, including the cell theory and the differences between unicellular and multicellular organisms. This quiz covers key historical discoveries and the significance of cells in living organisms. Test your knowledge of essential cell biology principles!
