Module 1 - Unit 3 Flashcards
Name factors that affect the rate of diffusion
○ Molecular Weight ○ Temperature ○ Membrane Permeability ○ Pressure ○ Dreection of Fluid Flow ○ Concentrations
What are the 2 main types of endocytosis?
Phagocytosis
Pinocytosis
Describe endocytosis
Endocytosis: substance that are too large to pass through the cell membrane are transported across by a process called endocytosis
Describe Phagocytosis
Involves ingestion of large particles by the plasma membrane
The membrane attaches itself to the particle and vaginates outwardly and completely engulfs the object
The phagocytic vesicle is pinched off the cell wall and moves to the interior of the cell
Explain the process of active transport and its importance in biological systems.
- Some substances that are impermeable and must be pumped across the membrane since they are needed for metabolic processes
- Active transport proteins are molecular pumps that pump molecules against a concentration gradient
- These pumps require energy from ATP
Define Atrophy
Shrinkage in the size of the cell by loss of cell substance is known as atrophy.
What are causes of atrophy?
· Decreased workload · Loss of innervation · Diminished blood supply · Inadequate nutrition · Loss of endocrine stimulation · Aging
Define Hypertrophy
Hypertrophy refers to an increase in the size of cells and, with such change, an increase in the size of the organ. The hypertrophied organ has no new cells, just larger cells
Define Hyperplasia
Hyperplasia constitutes an increase in the number of cells in an organ or tissue, which may then have increased cell volume.
What can Hyperplasia be divided into? (2)
- Physiologic hyperplasia which can be further divided into hormonal and compensatory. An example of hormonal hyperplasia is the proliferation of the glandular epithelium of the female breast at puberty and during pregnancy. An example of compensatory hyperplasia is that which occurs when a portion of the liver is removed.
- Pathologic hyperplasia instances of excessive hormonal stimulation or the effects of growth factors on target cells.
Define Necrosis
There are two morphological patterns of cell death, necrosis and apoptosis. Necrosis is the more common type of cell death after exogenous stimuli, occurring after such stresses as ischemia and chemical injury, and is manifested by severe cell swelling or cell rupture, denaturation and coagulation of cytoplasmic proteins, and breakdown of cell organelles.
Define Apoptosis
Apoptosis is a more regulated event. It is designed for the normal elimination of unwanted cell population during embryogenesis and various physiologic processes. There is some overlap between these two processes.
What are causes of cell injury?
Hypoxia Physical Agents Chemical Agents and Drugs Infectious Agents Immunologic reactions Genetic derangements Nutritional imbalances
see p. 34 for details**
What is Hypoxia?
d) Hypoxia: Most common cause of cell injury, impacts on aerobic oxidative respiration. Loss of blood supply (ischemia), which occurs when arterial flow is imbedded is the most common cause of hypoxia. Another cause is inadequate oxygenation of the blood due to cardiorespiratory failure. Loss of the oxygen carrying capacity of the blood, as in anemia or carbon monoxide poisoning is a third less frequent basis for oxygen deprivation. Depending on the severity of the hypoxic state, cells may adapt, undergo injury, or die.
What are physical agents?
Physical Agents: Physical agents include mechanical trauma, extremes of temperature (burns and deep cold), sudden changes in atmospheric pressure, radiation, and electric shock.
What are Infectious agents?
These agents range from submicroscopic viruses to large tapeworms.
What are genetic derangements?
Genetic derangements: The genetic injury may result in congenital malformations or in subtle alterations in the coding of hemoglobin S in sickle cell anemia.
Give examples of symport and antiport active transport systems.
Symport: two molecules move simultaneously in the same direction
Antiport: two molecules move simultaneously in opposite direction.
What is the smallest functional unit in the body?
Cells
How many distinguishable cell types are there?
more than 200
Similar cells are organized into _____.
tissues
Different tissues are organized into _______.
organs
Several different organs combine to perform a more extensive functions and are then referred to collectively as____________.
Organ System
What are the basic requirements of every cell?
Obtain materials ( required for growth, maintenance and reproduction of the cell) and a source of energy ( for the performance of all kinds of work)
What are the 3 main components of cells?
1- Nucleus
2- Cytoplasm
3- Cell Membrane
True or False?
The nucleolus is always singe
False
Can be single or multiple, and its role is to synthesize and assemble the RNA molecules and numerous proteins that make up the ribosomes
What are the roles of the nucleus?
- Store genes on chromosomes
- Organize genes into chromosomes to allow cell division
- Transport regulatory factors and gene products via nuclear pores
- Produce messages
- Produce ribosomes in the nucleolus
- Organze the uncoiling of DNA to replicate and decode key genes
True or False
The nucleus is the control centre of the cell?
True
it determines what is synthesize, how much is synthesized, and how it is synthesized.
Which part of the Endoplasmic Reticulum is covered with ribosomes?
The Rough ER
Is the ER structurally continuous of the outer membrane of the nuclear envelop?
Yes
What is the main function of the smooth ER?
lipid and carbohydrate metabolism
What do mitochondria look like?
sausage shaped! and really small, about the size of a bacteria.
What is the power plant of the eukaryotic cell?
mitochondria ( manufactures most of the cellular ATP)
Is the Golgi apparatus an extension of the endoplasmic reticulum?
yes
What is the function of the Golgi apparatus?
sorting, modifying, and packaging macromolecules that have been secreted by the ER.
What is involved in the formation of lysosomes and peroxisomes?
- The ER
- The Golgi Apparatus
What is responsible for the digestion of foreign substances?
Lysosomes
Name the 3 types of cytoskeletal filaments
- microtubules
- actin filaments
- intermediate filaments
What are microfilaments made up of?
protein called actin
The continual assembly and disassembly of microfilaments is important for cell _______.
motility
Intermediate filaments and microtubules are formed from other proteins such as ________.
keratin
What do intermediate filaments contribute to?
the mechanical sterility of the cell
True or False
Microtubules have structural and contractile roles in all cells
True
What are the 2 distinct populations of ribosomes? what is their different roles?
1- those bound to the endoplasmic reticulum
2- those that are not visibly bound to any membrane
- the free ribosomes leave the newly formed protein in the cytoplasm while the bound ribosomes transfer the newly synthesized protein to the interior of the endoplasmic reticulum.
What is the intracellular fluid in which the membrane-structured organelles are located called?
Cytoplasme
What types of substances does the cytoplasm contain?
- enzymes and other metabolites which are required in the various metabolic processes
The _____________ is a thin film which separates the cell content form the external environment.
Plasma Membrane
what is the common structure within all biological membranes
continuous lipid bilayer
Are the tails of the phospholipids hydrophilic or hydrophobic?
hydrophobic
The membranes of cells are fluid; semi-permeable. What does that mean?
Some things can ass throughout the membrane through osmosis or diffusion while others can’t.
The rate of diffusion varies on certain factors. Name some.
size,
polarity,
charge and concentration on the inside of the membrane VS the concentration on the outside of the membrane.
What is the difference between extrinsic or intrinsic proteins?
Extrinsic membrane proteins are entirely outside of the membrane
Intrinsic membrane proteins are embedded in the membrane
Intrinsic membrane proteins are also called ____________.
transmembrane proteins
Wat are membrane proteins involved with?
- transport processes such as channels for Na+ and K+ and for calcium
- communication between cells as in gap junctions
- energy transfer
- receptor sites for specific substances
- carry out many biosynthetic functions
Why are carbohydrate groups on the cell membrane important?
- help maintain the asymmetry of the plasma membrane
- are involved with intercellular recognition
- provide the potential for structural diversity
- help in the orientation of glycoproteins in membranes
What are the 2 major types of membrane proteins?
- transporters
- receptors
Name the three categories of transport mechanism
- Simple/Passive Diffusion
- Facilitated Diffusion
- Active Transport
The processes that are involved with the movement of substances across membranes are:
- diffusion
- facilitated diffusion
- active transport
- endocytosis ( pinocytosis and phagocytosis)
- exocytosis
Diffusion is the movement of a substance from an area of _______ concentration to an area of ________ concentration.
high, low
How is facilitated diffusion different from simple diffusion?
facilitated diffusion requires a carrier protein to transport the substance across the membrane
The process of simple diffusion across a permeable membrane is dependent on what factors?
- Molecular Weight
- Temperature
- Membrane Permeability
- Pressure
- Direction of Fluid Flow
- Concentration
** see p. 19-20 for more details regarding these**
The speed of facilitated transport is limited by ____________ whereas the speed of diffusion is dependent on the _____________.
number of protein channels available
concentration gradient
Define Osmosis
the process of net movement of water caused by a concentration difference of water on either side of a membrane
Define Osmotic Pressure
the pressure required to stop osmosis completely
Active transport proteins are molecular pumps that pump molecules ________ a concentration gradient.
Against ( therefore needs energy)
Active transport is different from facilitated diffusion in that active transport requires __________.
Energy derived from ATP
What are the 4 functions that a carrier protein must be able to perform to transport substances?
1- recognition
2- translocation
3- release
4- recovery
see p. 23 for details
When a molecule movies in only 1 direction, it is called________.
Uniport
When 2 molecules move simultaneously in the same direction, it is called__________.
Symport
When 2 molecules move simultaneously in opposite directions, it is called__________.
Antiport
Descripbe Pinocytosis
similar to phagocytosis exept it is more widespread since it occurs at the cell membranes of most cells and involves the formation of very small vesicles containing extracelluar fluid called pinocytic vesicles.
p. 23
The excretion of intracellular macromolecules to the outside of the cell is called ___________.
Exocytosis
occurs in the opposite manner to pinocytosis
What are the 2 major reasons that cells need to separate themselves from the outside environment?
1) it must keep its molecules of life (DNA, RNA, and it’s assortment of proteins) from dissipating away
2) It must keep out foreign molecules that damage or destroy the cells components and molecules.
What controls the rate of metabolic processes?
Protein catalysts, called enzymes
The human body is composed of and estimated_________ cells that can be differentiated according to their specific function in the various tissues and organs?
75 trillion
What are the 3 types of Intercellular Junctions?
1) Adhering Junctions ( mechanically anchor cells together to maintain tissue integrity)
2) Impermeable Junctions
3) Communicating Junctions
** see. p. 31 for more details**
What are the 4 aspects of the disease process that form the core of pathology?
1) Etiology of disease
2) Pathogenesis
3) Morphologic changes
4) Clinical significance
** see p. 32 for details on these**
What does cellular adaptation involve?
- regulation of specific cellular receptors
- induction of new protein synthesis by target cells
- recepetor binding, signal transduction, transcription, translation
- regulation of packaging and release
