Chapter 4 : Cell Structure Flashcards
Who invented the microscope?
Robert Hook
The cell theory states 3 things:
- All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells.
- Cells are the smallest living things, the basic units of organization of all organisms
- Cells arise from ONLY division of previously existing cell
Rate of diffusion is affected by a number of variables including
- Surface area
- Temperature
- Concentration gradient of diffusing substances
- distance over which diffusion occurs
Why can’t we see cells?
the limited resolution of the human eye
Resolution
The minimum distance between two points can be apart and still be distinguished as two separate pieces
4 Major feature that make up ALL cells
- A nucleotide or nucleus
- Cytoplasm
- Ribosomes
- Plasma Membrane
Where does DNA reside in prokaryotes?
nucleoid
Cytoplasm
A semifluid matrix filling the interior of the cell
Cytosol
Part of cytoplasm that contains organic molecules and ions
What is the simplest organisms?
Prokaryotic cells
What are the two prokaryote domains?
Archaea and bacteria
What is the role of a cell wall?
Protects the cell, Maintain it’s shape, and prevents excessive uptake or loss of water
What are most bacteria cell walls composed of?
Petidoglycan
What are archaea cell walls composed of?
Polysaccharides, proteins, and inorganic components
Flagella
Long, threadlike structures protruding from the surface of a cell that are used in locomotion
Nucleolus
Site of rRNA synthesis
Nuclear Envelope
A structure that surrounds the nucleus made of two phospholipid bilayer membrane.
Chromatin
A substance within a chromosome consisting of DNA and protein
Endoplasmic reticulum
Largest internal membrane, composed of phospholipid bilayer and embedded with proteins
Rough Endoplasmic Reticulum (RER)
Processes and Transports proteins made at attached ribosomes
Smooth Endoplasmic Reticulum (SER)
Fatty acid and steroid (lipid) synthesis and detoxifies toxic substances
Golgi Apparatus
A complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells; involved in secretion and intracellular transport from the ER to other parts of the cell
Lysosome
A small, round structure with various specialized metabolic functions
microbody
A cellular organelle bounded by a single membrane and containing a variety of enzymes; generally derived from endoplasmic reticulum
Peroxisome
Microbodies that contain enzymes used to oxidize fatty acids
Central Vacuole
A membranous sac in plant cells that functions cell tonicity and store nutrients / waste products
Mitochondria
Organelle called the powerhouse. Consist of outer membrane, a complex inner membrane that produces energy for the cell in the form of ATP
Cristae
Folds in the inner membrane of mitochondria
Matrix
Inner membrane containing proteins for oxidative metabolism
Intermembrane space
Outer compartment lying between two mitochondrial membranes
chloroplast
A cell-like organelle present in algae and plants that contains chlorophyll (and usually other pigments) and carries out photosynthesis.
Thylakoids
A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
Stroma
The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.
amyloplast
A plant organelle called a plastid that specializes in storing starch.
plastid
An organelle in the cells of photosynthetic eukaryotes that is the site of photosynthesis and, in plants and green algae, of starch storage.
endosymbiosis
Theory that proposes that eukaryotic cells evolved from a symbiosis between different species of prokaryotes.
Eukaryotic cells contain three types of cytoskeletal fibers including..
Actin filaments, microtubules, and intermediate filaments
Actin Filaments
1/3 of the elements that make up the cytoskeleton, also called microfilaments.
Microtubule
A long, hollow protein cylinder, composed of the protein tubulin; this influence cell shape, move chromosomes in cell division, and provide the function internal structure of cilia and flagella.
Intermediate Filaments
A cytoskeletal element made up of fibrous lamin protein that is intermediate in size between microfilaments and microtubules.
Centrioles
Organelle made of 2 cylinders of microtubules, located in the nucleus, help to organize cell division and form basal bodies
Cilia
Hair like projections made of microtubules that extend from the plasma membrane and used for locomotion
Flagella
Whip like tails made of microtubules found in single cell organism to aid in movement
Which of the following is the main function of intermediate filaments?
To enable cells to withstand the mechanical stress that occurs when cells are stretched
adherens junction
A form of adhesive junction found between cells in many organisms. The most ancient cell junctions, these contain the Ca2+-dependent adhesion molecule cadherin.
cadherin
One of a large group of transmembrane proteins that contain a Ca2+-mediated binding between cells; these proteins are responsible for cell-to-cell adhesion between cells of the same type.
desmosome
A type of anchoring junction that links adjacent cells by connecting their cytoskeletons with cadherin proteins.
septate junction
A type of tight junction between animal cells that forms a waterproof barrier.
tight junction
Region of actual fusion of plasma membranes between two adjacent animal cells that prevents materials from leaking through the tissue.
gap junction
A junction between adjacent animal cells that allows the passage of materials between the cells.
plasmodesmata
In plants, cytoplasmic connections between adjacent cells.
Eukaryotic cells are more complex than prokaryotic cells. Which of the following are found only in a eukaryotic cell?
Endoplasmic reticulum
Which of the following are differences between bacteria and archaea?
The molecular architecture of their cell walls
Ca Ions are stored in the
smooth endoplasmic reticulum
