CH 1 The Cell in Health and Illness Flashcards
Disease is initiated at what level?
The cellular level
Organelles
Specialized intracellular structures that carry out specific tasks to sustain life
Cells functions:
- internal processes vital for the body’s normal physiological function
- sense and respond to external environment and freely exchange materials and energy with surroundings
- ensure homeostasis
Plasma membrane is
cells barrier separating extracellular and intracellular environments and protection of organelles from injury. Made of phospholipid bilayer containing proteins and cholsterol.
Cytoplasm
Gel-like colloidal internal fluid environment containing ions, proteins, carbohydrates, and lipids that suspends cellular organisms inside the cell
DNA
Deoxyribonucleic acid
Nucleus
contains genetic material that ultimately regulates cellular activity
Disease arises most commonly from
dysfunction of one or more cellular organelles, proteins, or biochemical processes
Plasma membrane permeability
SEMIpermeable
- extracellular fluid, intracellular fluid, ions, and other molecules diffuse back and forth.
- core lipid region remains impermeable to water but allows lipid soluble substances like oxygen and carbon dioxide to diffuse across
Plasma membrane proteins
some include ion channels for exchange with extracellular environment
Cellular edema
when excess fluid enters the cells internal environment and causes swelling.
Disrupts organelle function
Cellular dehydration
cellular fluid leaks out of the cell pores, causing shrinkage.
Disrupts organelle function
Glycoproteins
Carbohydrates attached to plasma membrane proteins
surface markers also called antigens
Antigens
glycoproteins that identify cells as a part of the body’s own tissues. Ex: blood cells have A, B, O antigens.
Cellular ion concentration (Na+/K+)
Optimal cell function requites Sodium (Na+) concentration to be higher OUTSIDE the cell and potassium (K+) to be higher INSIDE the cell.
PLasma membrane solubility to Na+/K+
More soluble to K+ (potassium) ions
Active transport by Na+/K+
uses adenine triphosphate (ATP) to move pump sodium and potassium in opposite directions across plasma membrane.
For every three sodium out, two potassium are pumped in.
Sodium-Potassium pump responsibilities
Maintaining resting potential and cell fluid volume
-in animals responsible for 1/2 of cells energy expenditure
Na+/K+ can by pharmacologically altered
True. Ex: cardiac glycosides slow don pump and keep more calcium in heart muscle cells to strengthen muscle contraction
Mitochondria
Cells energy producers (the powerhouse of the cell)
Mitochondria main function
to convert organic nutrients into cell energy in the form of ATP
Aerobic metabolism
the process, requiring oxygen, to produce energy in the form of ATP
Cell hypoxia
When no oxygen is available for the cells
Anaerobic metabolism
Non-oxygen metabolism, also called glycolysis, when glucose is used to create energy.
of ATP produced by aerobic metabolism
34 net yield
of ATP produced by anaerobic metabolism
Net energy yield of 2 ATP + pyruvic acid
Pyruvic acid converted into what does what
acetyl-coenzyme A triggering the Krebs or citric acid cycle
Krebs cycle
also known as the citric acid cycle, with oxygen, mitochondria produce 34 ATP
Pyruvic acid in cellular hypoxia
converted to lactic acid, noxious to cells causing muscle pain
Mitochondria are the only organelles that have their own DNA? T/F?
True
Exercise stimulates formation of increased numbers of mitochondria in muscle cells, because of this:
the muscle uses more oxygen and yields more energy