Chapter 4: Cell Structure Flashcards
One of the fundamental concepts of Biology
Cell theory
All cells have at least 3 components in common. What are they?
- plasma membrane
- Cytoplasm
- DNA
A cell’s outermost membrane is called_____. A characteristic of this membrane is that it is selectively ______.
Plasma membrane
Selectively permeable
A jelly-like substance of water, sugars, ions, and proteins
Cytoplasm
A cell’s hereditary information that guides development and other metabolic functions
DNA
When a cell increases its size, it’s volume increases faster than its surface area
Surface-to-volume-ratio
All cell membranes are composed primarily of a
Phospholipid bilayer
Cell membranes are described as a fluid _______.
Mosaic
Why are cell membranes described as a “fluid” mosaic?
Because the phospholipids are not chemically bonded to one another
Why are cell membranes described as a fluid “mosaic”?
Because the cell membrane is a mixed composition of lipids and embedded/attached proteins
What are the 4 types of proteins associated with a cell membrane?
- ADHESION PROTEINS
- RECOGNITION PROTEINS
- RECEPTOR PROTEINS
- TRANSPORT PROTEINS
In a cell membrane, what is the function of adhesion proteins?
Help cells stick together in some animal tissues
In a cell membrane, what is the function of recognition proteins?
Identify “self” cells as well as foreign cells
In a cell membrane, what is the function of the receptor proteins?
Trigger a change in cell activity by binding substances to the cell membrane
In a cell membrane, what is the function of the transport proteins?
Passively or actively assist with the movement of ions or molecules across the membrane
What are the 2 smallest/simplest and most diverse forms of life?
Single felled bacteria and archaea
Protects and controls access to DNA
Nucleus
Makes & modifies new polypeptides and lipids
Endoplasmic reticulum (ER)
Modifies proteins and lipids, then packages the finished products and ships them out into the vesicles
Golgi body
Stores, transports, or breaks down their contents (includes central vacuole in plants)
Vesicles
Double-membraned organelles that produce ATP by aerobic respiration
Mitochondria
Double membraned organelles that function in photosynthesis l, storage, or pigmentation
Plastids
Fluid-filled vesicle that breaks down cellular wastes and debris, including carbohydrates, proteins, nucleus acids, and lipids
Lysosome
Enzyme-filled vesicle that Breaks down fatty acids, amino acids, and toxins
Peroxisome
Fluid-filled vesicle that isolates or disposes of waste, debris, or toxic materialistic
Vacuole
Assembles polypeptides
Ribosome
Serves as an Anchor for cytoskeleton
Centriole
Dynamic network of interconnected protein filaments that supports, organizes, and moves eukaryotic cells & their parts
Cytoskeleton
Plant cells DO have a _________, _________, and _________; animal cells DO NOT
Cell wall, central vacuole, and chloroplasts
The outer boundary of the nucleus which controls access to DNA; made up of 2 lipid bilayers
Nuclear envelope
Viscous fluid enclosed by the nuclear envelope
Nucleoplasm
A dense, irregularly shaped region where ribosomal subunits are assembled
Nucleolus
Organized cluster of proteins that selectively allow proteins, ribosomal subunits, and RNA to move through the nuclear envelope
Nuclear pores
Interacting organelles b/w the nucleus and plasma membrane that make, modify, and transport lipids and proteins, as well as recycle and dispose of waste
Emdomembrane system
Modified proteins made by ribosomes attached to it
Rough ER
Makes lipids, breaks down carbohydrates and fats, and inactivated toxins
Smooth ER
Specialized plastic for photosynthesis in some Protista and plant cells
Chloroplasts
Oxygen requiring reactions that occur inside the mitochondria
Aerobic respiration
What are the 3 components of a choloroplast’s structure
- stroma ( semifluid containing enzymes and chloroplast DNA)
- 2 outer membranes
- thylakoids (inner membrane system folded into flattened disks called grana)
The best hypothesis for the origin of eukaryotic cells.
Proposal that eukaryote organelles evolved from prokaryotes that took up permanent residence inside a host cell
Theory of Endosymbiosis
What are the 3 components of the cytoskeleton?
- Microtubules
- Microfilaments
- Intermediate filaments
Component of the cytoskeleton that’s Made of the subunits of the protein Tubulin ; assemble and disassemble
Microtubules
Component of cytoskeleton;
Made of actin subunits;
In cell cortex, they serve as reinforcing mesh under a plasma membrane
Microfilaments
Component of cytoskeleton;
Most stable of cytoskeleton
Lends structure and resilience to cells
Intermediate filaments
Move cell parts; “walks” along the cytoskeleton fiber to assist transport
Motor proteins
“False feet”;
Move the cell and engulf prey;
Elongating micro filaments force a bulge outward;
Motor proteins attached to microfilaments drag the plasma membrane
Pseudopods
Secretion of eukaryotic organisms;
Mixture of fibrous proteins and polysaccharides
Extracellular matrix (ECM)
What are the 3 types of cell junctions in animal tissues?
- Tight junctions
- Adhering junctions
- Gap junctions
Cell junction (animal)
Rows of adhesion proteins
Prevent fluids from seeping between cells
Tight junctions
Cell junction(animal)
Adhesion proteins that anchor cells to one another
Prevalent in contractile tissue
Adhering junction
Cell junction (animal) Closable channels Connect to cytoplasm of adjacent cells Permits water, ions, and small molecules to pass directly from one cell to another
Gap junctions
Plant tissues have ____ type(s) of cell junction(s)
One
Cell junction (plant)
Extends across cell walls
Connects cytoplasm and ER of adjoining cells
Plasmodesmata
