Module 1: Cell and Molecular Physiology Flashcards
Ability to maintain stable environment; The goal of all physiologic processes
Homeostasis
Maintenance of nearly constant conditions in the internal environment
Homeostasis
Internal environment for our trillions of cells
Milieu interieur
T or F: ECF maintains the internal environment or milieu interieur.
T
2/3 of TBW
ICF
1/3 of TBW
ECF
Plasma is ____ of the ECF while, interstitial fluid is ____.
1/4; 3/4
A 70kg man is approximately composed up of 42 liters of water. How much of the man is...? A) ICF B) ECF C) IF D) Plasma
A) ICF=0.4 x 70kg=28L
B) ECF=0.2 x 70kg=14L
C) IF=0.75 x 14L=10.5
D) Plasma= 0.25 x 14L=3.5L
Note: TBW(60%), ICF(40%), ECF(20%), Plasma(25% of ECF), IF(75% of ECF)
Systems involved in regulation of body functions
Nervous system; Hormone system; Immune system, Integumentary system
Nervous system regulates body functions through its _____, _____, _____ and, _____ control.
Input (sensory), Integrative (CNS), Output (motor), Autonomic
This system distinguishes its own cells from foreign cells and substances and, destroys invades by phagocytosis or by producing sensitized lymphocytes or special proteins.
Immune system
Reaction time: Nervous vs Hormonal
Fast; Slow
Mediators: Nervous vs Hormonal
Neurons; Hormones
Type of message: Nervous vs Hormonal
Electrical impulse; Organic message
Response target: Nervous vs Hormonal
External envt; Internal envt
Linking mechanism: Nervous vs Hormonal
Nerves/ synapses; Blood/circulatory
Effectors: Nervous vs Hormonal
Muscles and glands; Organ systems
Function: Nervous vs Hormonal
Nervous coordination; Chemical/metabolic coordination
Boundary between the body’s internal environment and the outside world
Integumentary system
The degree of effectiveness with which a control system maintains constant condition
Gain of control system
Formula for GAIN
Gain=correction/error
Feedback mechanisms are mostly ______ in nature.
Negative
Series of changes that return the factor toward a certain mean value
Negative feedback
Blood clotting: neg or pos feedback?
Positive
Child birth: neg or pos feedback?
Positive
Feed-forward control is also known as
Adaptive control
A form of delayed negative feedback
Feed-forward control
Basic unit of life
Cell
A collective term for different substances that make up the cell
Protoplasm
Protoplasm is composed mainly of five basic substances and what are these?
Water Electrolytes Proteins Lipids Carbohydrates
Principal fluid of the cell
Water
Water us present 70% to 85% in most cells except for? (2)
Fat cells; Bone cells (less h2o)
Inorganic chemicals for cellular reactions
Electrolytes
Proteins can be classified into:
Structural; Functional
Long intracellular filaments that form microtubules and fibrillar proteins, examples are cytoskeleton of cellular organelles and fibrillar proteins in collagen and elastin fibers
Structural proteins
Composed of combinations of a few molecules in tubular-globular form, examples are enzymes
Functional proteins
Soluble in fat solvents but insoluble in water
Lipids
2% of total cell mass; forms the cell membrane and membrane barriers
Phospholipids and cholesterol
In fat cells, this constitutes 95% of cell mass
Triglycerides (neutral fat)
Has little structural function in the cell except as parts of glycoprotein molecule; cellular nutrition
Carbohydrates
Thin, pliable, elastic structure
Cell membrane
Composition of the cell membrane
Proteins-55% Phospholipids-25% Cholesterol-13% Other lipids-4% Carbohydrates-3%
The fluid mosaic model is conceptualized by
Singer and Nicholson in 1972
Fluid mosaic model?
Cell membrane is composed of phospholipid bilayer
Parts of the cell membrane
Phospholipid bilayer
Membrane proteins
Membrane carbohydrates (glycocalyx)
Other membrane lipids
T or F: In the phospholipid bilayer, the phosphate end is hydrophobic.
F. It is hydrophilic or soluble in water.
The fatty acid end of the phospholipid bilayer: hydrophobic or hydrophilic?
Hydrophobic. Soluble only in fats
Possession of both hydrophilic and hydrophobic properties
Amphipathic
Integral proteins are anchored and embedded in the cell membrane through _________ interactions.
Hydrophobic
This type of proteins may span the cell membrane
Transmembrane proteins
These proteins are not embedded in the cell membrane.
Peripheral proteins
Peripheral proteins are loosely attached to the cell membrane by?
Electrostatic interactions
Motor protein which drives transport form the center to the periphery
Kinesin
Motor protein which drives transport from the periphery to the center
Dynein
Loose carbohydrate coat of cell membrane
Glycocalyx
Functions of glycocalyx
Imparts a negative electrical charge
Attachment for other cells
Receptor substances for binding hormones
Immune reactions
Functions of cholesterol
Determine the degree of permeability of the bilayer to water-soluble constituents
Controls much of the fluidity of the membrane
Specialized cellular subunit found in the cytoplasm that has a specific function; usually membrane-bound
Cellular organelles
Provide rigid physical support for certain parts of the cells (intracellular scaffolding)
Cytoskeleton
Cytoskeleton: fibrillar proteins synthesized by _______ in the cytoplasm.
Ribosomes
Give two examples of cytoskeleton
Filaments: actin filaments in cytoplasm, actin and myosin filaments in muscles
Microtubules: flagellum in sperm, cilia in respiratory tract, centrioles, mitotic spindle
Powerhouse of the cell
Mitochondria
Mitochondria forms ______ used for membrane transport, synthesis of chemicals and mechanical work
ATP
T or F: Mitochondria
A. Self-replicative
B. Has its own DNA that is paternally-derived
C. Has its own genetic code
A. T
B. F, maternally-derived mitochondrial DNA
C. T
Network of tubular and flat vesicular structures
Endoplasmic reticulum
Machinery for major metabolic functions of the cell
Endoplasmic reticulum
RER is also called
Granular ER
RER is composed of large numbers of _______ attached to its outer surface
Ribosomes
- mixture of RNA and proteins
- function in protein synthesis
T or F: all ribosomes in a cell are bound to RER.
F, not all
Also called Agranular ER
SER
T or F: SER also has attached ribosomes on its surface.
F, no attached ribosomes
Functions of SER
Detoxification of substances
Synthesis of lipids
Smooth ER in skeletal muscles
Sarcoplasmic reticulum
Rough ER in neurons
Nissl substance
Composed of four or more stacked layers of thin, flat, enclosed vesicles lying near one side of the nucleus
Golgi apparatus
Functions of Golgi apparatus
Packaging of proteins
Molecular tagging
Vesicular organelles that form by breaking off from the Golgi apparatus
Lysosomes
Only protein that is modified in the RER and not in Golgi
Collagen
Suicide bags of cells
Lysosomes
Formed by self-replication or budding off from SER
Peroxisomes
Peroxisomes contain these enzymes (2)
Oxidase, Catalase
Also called secretory granules
Secretory vesicles
Functions of secretory vesicles
Storage of proenzymes
Replenish the plasma membrane whenever it forms phagocytic or pinocytic vesicles
Control center of cells
Nucleus
Also called nuclear envelope
Nuclear membrane
T or F: Nucleolus does not have limiting membrane.
T
