Biology Chapter 6 Quiz

Cell Structure and Organelles

• "Essential Cell Biology" by Bruce Alberts et al., Garland Science, 2014
• This text provides a summary of cellular structures and organelles

Historical Landmarks in Determining Cell Structure

• 1665: Robert Hooke observed small chambers in cork, naming them "cells."
• 1674: Antony van Leeuwenhoek discovered protozoa and bacteria.
• 1833: Robert Brown described the cell nucleus.
• 1839: Schleiden and Schwann developed the cell theory (the cell is the basic unit of life).
• 1857: Rudolf Kölliker described mitochondria in muscle cells.
• 1879: Walther Flemming described chromosome behavior during mitosis.
• 1881: Cajal and others developed staining techniques for nerve cells.
• 1898: Camillo Golgi described the Golgi apparatus.
• 1902: Theodor Boveri connected chromosomes and heredity.
• 1952: George Emil Palade, Keith R. Porter, and Kaj Sjöstrand developed electron microscope techniques.
• 1957: J. David Robertson described the cell membrane bilayer structure.
• 1960: John Cowdry described first detailed protein structure.
• 1965: Christian de Duve and colleagues separated peroxisomes, mitochondria, and lysosomes.
• 1968: Petran and collaborators created the first confocal microscope.
• 1970: Frye and Edidin demonstrated that cell membranes are fluid.
• 1974: Lazarides and Weber used fluorescent antibodies to stain the cytoskeleton.
• 1994: Chalfie and collaborators introduced green fluorescent protein (GFP).

Prokaryotic Cell Structure and Function

• Prokaryotes (bacteria and archaea): smaller, simpler cells, with a single membrane
• Cytoplasm contains DNA in nucleoid area
• Cell wall outside of plasma membrane
• Periplasmic space between plasma membrane and cell wall
• Outer membranes in Gram-negative bacteria

The Eukaryotic Cell

• Eukaryotes (e.g., plants, animals, fungi) are larger, more complex cells with a nucleus and other organelles.
• Some live as single cells, others in multicellular organisms
• More complex than bacteria and archaea

The Complexity of a Single Cell

• Extremely complex systems within single cells

All Eukaryotic Cells Have the Same Basic Set of Membrane-enclosed Organelles

• Eukaryotic cells contain membrane-bound organelles
• Examples: mitochondria, Golgi apparatus, endoplasmic reticulum, nucleus, lysosomes, peroxisomes, ribosomes, endosomes

Relative Volumes of Intracellular Compartments in a Liver Cell

• Table shows relative volumes of various compartments (e.g., cytosol, mitochondria, rough ER, smooth ER, Golgi cisternae, nucleus, peroxisomes, lysosomes, endosome) within a liver cell (Hepatocyte).

Relative Amounts of Membrane Types in Two Kinds of Eukaryotic Cells

• Table shows relative amounts of different membrane types in liver hepatocytes and pancreatic exocrine cells.
• Demonstrates the differing amounts for different parts of the cell.

Eukaryotic Cell Structure and Function (Plant and Animal Cells)

• Animal cells typically have round or irregular shapes, with 10–30 µm length
• Plant cells typically have rectangular or cubic shapes, with 10–100 µm length
• Distinguishing cell features include cell walls, chloroplasts, vacuoles; cilia and flagella; centrioles and centrosomes.

Cell Differences (Venn Diagram)

• Shows similarities and differences between plant and animal cells in terms of structures and functions

Cells Form Tissues in Plants and Animals

• Microscopic images of plant (fern root tip) and animal (kidney) tissues are shown.
• Shows how cells combine to create tissues

Eukaryotic Cells

• Eukaryotic cells contain a nucleus and various organelles.
• The acquisition of mitochondria and chloroplasts are crucial aspects for the evolution

Plasma Membrane

• Defines the cell boundary.
• Regulates homeostasis (internal balance).
• Communicates with other cells.
• Supports cell shape.
• Contains phospholipids, proteins, and cholesterol.

Cytoskeleton

• An array of fibrous proteins within the cytoplasm.
• Three classes: microtubules, microfilaments, and intermediate filaments.
• Maintains cell shape and controls movement of structures within the cell.
• Essential for cell division

Microtubules

• Help distribute chromosomes during cell division.

Cilia and Flagella

• Found on the cell surface.
• Provide movement.
• Composed of microtubules.
• Used in various functions like respiration or reproduction.

Male Sex Cells - Sperm

• Diagram shows head (contains acrosome, nucleus, centrioles), midsection (mitochondria), and tail (flagellum)

Nucleus

• Contains the genetic information (DNA).
• Composed of nuclear envelope, nuclear pores, nucleolus, chromatin, nuclear membrane, cytosol

Introduction (Nucleus)

• Displays components of a cell's nucleus (nuclear pores, membranes etc.)

Chromosome Behavior (S-Phase and Sister Chromatids)

• Shows diagrams of chromosomes during the S phase

Extensive System of Membranous Organelles

• Explains the purpose of a typical animal cell's nucleus and the different parts of it (e.g., the nuclear envelope, cytoplasm)

Endoplasmic Reticulum

• Extensive network of membranes within the cell
• Continuous with nuclear envelope
• Rough ER has ribosomes, smooth ER doesn't.
• Involved in protein synthesis, lipid synthesis.

The Endoplasmic Reticulum

• Produces components of eukaryotic cells.
• Has a continuous connection to the nuclear envelope.
• Rough ER has ribosomes and is involved in protein synthesis.

Golgi Complex

• Composed of a stack of flattened discs (cisternae).
• Modifies and packages proteins.
• Involved in secretion or transport to other destinations.

Transport Vesicles in Golgi Function

• The process of secretion and post-translational regulation. -Vesicles carrying molecules bud off from the ER and travel to the golgi apparatus
• proteins packaged and sent through the golgi
• vesicles leave the Golgi with modified molecules

Lysosomes

• Exclusive to animal cells.
• Degrade cellular components.
• Autophagy is a natural process for breaking down unnecessary cellular parts.
• Lysosomes contain enzymes for this breakdown.

Plant Vacuole

• Present in plant cells.
• Stores water and nutrients.
• Has a degradative function similar to lysosomes in animal cells.

Peroxisomes

• Contain a variety of enzymes.
• Responsible for various metabolic processes.
• Also involve breaking down hydrogen peroxide.
• Contain different enzymes that carry out oxidation reactions in plants and animals
• Similar to lysosomes, contain many enzymes for various chemical processes.

Mitochondria

• Generate usable energy (ATP) in aerobic cells (animals, fungi, plants).
• Found in all eukaryotic cells
• Contain their own DNA and ribosomes
• Have a distinctive structure with an outer and inner membrane

History (Mitochondria)

• Summarizes the historical discovery of Mitochondria.

Mitochondria Shape and Size

• Mitochondria can vary in size and shape

Mitochondria Structure

• Shows the structure of mitochondria by 2D & 3D diagrams.
• Explains the function of mitochondria in detail

Mitochondria (Main Site of ATP Production)

• Major sites for ATP production in cells.
• Contains a matrix, cristae, mitochondrial DNA, ribosomes, and other important structures

Energy Tally (ATP Production)

• Shows calculation of ATP produced in cells

Human Mitochondrial DNA (mtDNA)

• Shows the structure of mtDNA and the parts it codes for.

Chloroplasts

• Sites for photosynthesis in plants, algae
• Capture energy from sunlight
• Contain their own DNA and ribosomes

Chloroplasts Structure

• Displays the internal structures of chloroplasts by 2D & 3D diagrams -Contains a double membrane
• Thylakoid membranes inside chloroplasts.
• Site of photosynthesis inside plant (algae) cells.

Endocytosis and Exocytosis

• Eukaryotic cells continuously import and export materials through these processes.
• Vesicles form from the plasma membrane.
• Vesicles fuse with other organelles to deliver substances to and from them
• Vesicles with material bud off from the membrane and migrate
• Process is how substances are imported into and exported from the cell