A&P Chapter 3 Flashcards
Cell Theory
A cell is the structural and functional unit of life
How many different types of human cells are there?
250
What are the three basic parts of human cells?
Plasma membrane, cytoplasm, nucleus
The plasma membrane acts as an ______
Active barrier separating intracellular fluid from extracellular fluid
What is the lipid bilayer made up of?
75% Phospholipids, 5% Glycolipids, 20% Cholesterol
What does Cholesterol do for the lipid bilayer?
Increases membrane stability
What is integral proteins function?
Transport protein (channels and carriers), enzymes, or receptors.
What are integral proteins?
Transmembrane proteins. They go through the entire membrane
What are peripheral proteins?
Loosely attached to integral proteins that are attached to the surface
What are peripheral proteins function?
Functions as enzymes, motor proteins for shape change during cell division and muscle contractions, and cell to cell connections.
What do carbohydrates on the outside of the cell form?
The gluycocalyx
What cells are not bound to any other cells?
Blood cells and sperm cells
What are the three ways cells are bound together to form tissues and organs?
Tight junctions, desmosomes, gap junctions
What are tight junctions?
Impermeable junctions that form continuous seals around the cell and prevent molecules from passing between cells
Example of tight junctions
In the bladder to prevent leakage of urine
What are desmosomes?
Anchoring junctions that bind adjacent cells together and keeps cells from tearing apart
What is an example of desomosomes?
External layer of skin
What are gap junctions?
Communicating that allow ions and small molecules to pass from cell to cell.
What are gap cells important for?
Heart cells and embryonic cells
Example of gap junctions
Cardiac cells
What are the two ways substances cross the plasma membrane?
Passive transport and active transport
What is passive transport?
Where molecules move along a concentration gradient.
Does passive transport require energy?
No
What are the three types of passive transport?
Simple diffusion, facilitated diffusion, osmosis
What are the two types of active transport?
Primary active transport and secondary active transport
What is diffusion?
Natural movement of molecules from areas of high concentration to low concentration. Moving down a concentration gradient
What are the three types of diffusion?
Simple diffusion, carrier-mediated facilitated diffusion via protein carrier, and channel-mediated facilitated diffusion through a channel protein
What is simple diffusion?
Lipid-soluble molecules directly through the phospholipid bilayer
What is carrier-mediated facilitated diffusion via protein carrier?
Specific for one chemical; binding of solute causes transport to change shape
What is channel-mediated facilitated diffusion through a channel protein?
Mostly ions selected on basis of size and charge
What is osmosis?
Diffusion of water through a selectively permeable membrane
Water follows ______
Solute
What does water follows solute mean?
Water moves by osmosis from areas of low solute (high water) concentration to high areas of solute (low water) concentration
What does active transport require?
Carrier proteins
What do carrier proteins do for active transport?
Bind specifically and reversibly with the substance being moved. Some carriers transport more than one substance
What does active transport do?
Moves solutes their concentration gradient (from low to high)
What do antiporters do?
They transport one substance into the cell while transporting a different substance out of the cell
What do symporters do?
Transports two different substances in the same direction?
What is primary active transport?
Required energy comes directly from ATP hydrolysis. Uses a calcium pump and a Na-K pump
What is secondary active transport?
Required energy is obtained indirectly from ionic gradients created by primary active transport
What do vesicular transport processes in active transport include?
Endocytosis, exocytosis, transcytosis, and vesicular trafficking
What is endocytosis?
Transport into the cell
What are the three types of endocytosis?
Phagocytosis, pinocytosis, and receptor-mediated endocytosis
What is exocytosis?
Transport out of the cell
What is transcytosis?
Transport into, across, and then out of the cell
What is vesicular trafficking?
Transport from one area or organelle in the cell to another
What is the cytoplasm?
All cellular material that is located between the plasma membrane and the nucleus
What is cytoplasm composed of?
Cytosol and other inclusions
What is the cytosol?
Gel-like solution made of water and soluble molecules such as proteins, salts, sugars, etc
What are inclusions in the cytoplasm?
Insoluble molecules that vary with cell type
Examples of insoluble molecules that vary with cell type
Glucogen, granules, pigments, lipids, droplets, vacuoles, crystals
What are organelles?
Metabolic machinery structures of the cell, each with specialized function; either membranous or nonmembranous
What are the membranous organelles?
Mitochondria, ER, Golgi Apparatus, Peroxisomes, and lysosomes
What are the nonmembranous organelles?
Ribosomes, cytoskeleton, and centrioles
What is the mitochrondria?
The site of ATP synthesis in the cell
What does the mitochondria contain their own of?
DNA, RNA, and ribosomes
What are ribosomes?
The site of protein synthesis
What are the two switchable forms of ribosomes?
Free and membrane-bound ribosomes
What are free ribosomes?
Free floating; site of synthesis of soluble proteins that function in cytosol or other organelles
What are membrane-bound ribosomes?
Attached to membrane of the endoplasmic reticulum; site of synthesis of proteins to be incorporated into membranes or lysosomes, or exported from the cell
What are the two types of the endoplasmic reticulum?
Rough ER and smooth ER
What is the rough ER?
Large organelle that makes proteins and sends them to the golgi apparatus
What is the smooth ER?
The site of lipid and steroid synthesis and lipid metabolism
What is the golgi apparatus?
Organelle that packages proteins and forms lysosomes
What are peroxisomes?
Site of free radical neutralization and detoxification
What are lysosomes?
The site of intracellular digestion. Contains digestive enzymes and digests ingested bacteria, viruses, and toxins.
What do lysosomes degrade?
Nonfunctional organelles
What are the three types of the cytoskeleton?
Microfilaments, intermediate filaments, and microtubules
What are microfilaments?
Strands made of spherical protein subunits called actin
What are intermediate filaments?
Tough insoluble protein fibers constructed like woven ropes composed of tetramer (4) fibrils
What are microtubules?
Hollow tubes of spherical protein subunits called tubulin
What are microtubules?
Hollow tubes of spherical protein subunits called tubulin
What are microtubules?
Hollow tubes of spherical protein subunits called tubulin
What are centrioles?
A pair of barrel-shaped microtubular organelles that lie at right angles to each other. Newly assemble microtubules radiate from centrosome to rest of the cell.
What do centrioles aid in?
Cell division
What do centrioles form?
The basis of cilia and flagella
What are cilia?
Whiplike, motile extensions on surfaces of certain cells, used to propel substances across a cell
Example of cilia
In respiratory cells to sweep mucus along
What are cilia made up of?
Microtubules
What are flagella?
Longer extensions for movement of the whole cell
Example of flagella
Tail of sperm
What are flagella made of?
Microtubules
What are microvilli?
Minute, fingerlike extensions of plasma membrane that project from surface of select cells. Used to increase surface area for absorption
Example of microvilli
Intestinal and kidney tubule cells
What does the nucleus contain?
DNA
What is the nuclear envelope?
Double-membrane barrier that encloses the jelly-like fluid, the nucleoplasm
What do nuclear pores allow?
Substances to pass into and out of the nucleus
What is the nucleolus the site of?
Ribosomal assembly
Most cells are ______
Uninucleate (one nucleus)
Skeletal muscle, certain blood cells, and some liver cells are _______
Multinucleate (many nuclei)
Red blood cells are _________
Anucleate (no nucleus)
The cell cycle acronym
PMAT
What does PMAT stand for?
Prophase, Metaphase, Anaphase, Telophase
What order is the cell cycle?
Interphase –> Prophase –> Metaphase –> Anaphase –> Telophase –> Cytokinesis
What is prophase?
The miotic spindle, where it comes together
What is metaphase?
Where they line up
What is anaphase?
Where they are pulled apart
What is telophase?
Where the nucleolus forms, and the contractile ring at cleavage furrow
What is cytokenesis?
Cleavage furrow develops and the cytoplasm of the cell divides. Two daughter cells are pinched apart
When does cytokinesis begin?
During late anaphase and continues through mitosis
What is apoptosis?
Programmed cell death
What does cells does apoptosis cause to neatly self-destruct?
Cancer, infected, and old cells
What is hyperplasia?
Accelerated growth that increases cell numbers when needed
What are the two types of hyperplasia?
Physiologic, and pathologic
What is physiologic hyperplasia?
Occurs due to a normal stressor
What are examples of physiologic hyperplasia?
Increased thickness of endometrium during menstrual cycle, increased size of breast during pregnancy
What is pathologic hyperplasia?
Occurs due to an abnormal stressor
What is an example of pathologic hyperplasia?
Cell changes due to cancer
What is hypertrophy?
Increase in size that results from overstimulation or use
What is atrophy?
Decrease in size that results from loss of stimulatino or use
