Cell Structure and Function Flashcards
Dr. Huckle
Physiology
studies FUNCTION at all levels works with ALL The “ologies” as the organism as intergated systems along with the RESPONSES
Homeostasis
The organism’s ability to adapt to internal (endogenous) or external (exogenous) environmental conditions and stay STABLE
Basic Components of Feedback Control Systems
- Sensor: monitors the level of activity of a system or some environmental condition. Communicates with the…
- Integrator: receives information from the sensor, compares the info with a “set point” and communicates any adjustments to be made by…
- Effector: makes any adjustments, up or down, needed to bring the activity or system to alignment with the set point
Negative Feedback Systems
***controls most functions in physiologic systems
results of the feedback loop inhibit (inherently) stop the loop from continuing
Example: Blood pressure
Positive Feedback Systems
***rare but important
accelerate/amplify changes
can promote instability
increase the level of activity of a process leading to it’s own occurence
Example: Ovulation
Hierarchy or organization of animals
Cells
Tissues
Organs
Organ Systems
Organism
3 features found of each level of organization
- Communication among system components
- Homeostatic mechanisms that draw upon stored regulatory information
- Energy storage and utilization
Major classes of Biomolecules
carbs, proteins, nucleic acids, lipids
Proteins
Monomer: amino acids
Poylmer: proteins, polypeptide
Bonded by: amide (peptide) bond
Components: carboxyl group, amino group, R group side chain
Functions: structural elements, enzymes, chemical messengers, energy source
Nucleic Acids
Monomer: nucleotides
Poylmer: nucleotide chains
Bonded by: phosphodiester bonds
Components: nitrogenous base, sugar, phosphate group
Functions: information storage, energy intermediates, catalysts, structure
Function of lipids
Solubility barriers (membranes), structure, chemical messengers, energy source
Phospholipids
amphipathic molecules: hydrophobic fatty acid chain and hydrophilic polar head
Major components of membranes (phospholipid bilayer)
Carbohydrates
Monomer: monosaccharides
Poylmer: di-, oligo-, and poly saccharides
Bonded by: glycosidic bonds
Components:
Functions: fuel, energy storage, structure, cellular recognition, communication
4 features of cells
- ability to sense and respond rapidly to the surrounding conditions
- ability to access stored info for longer term changes in characteristics
- need to generate and utilize forms of chemical energy
- ability to interact with their surroundings
Distinguishing Features of Cells
function, size, shape, polarity, tissue adherence, responsiveness to specific stimuli, mitotic capacity, lifespan
Cell Organelles
Nucleus, Rough ER, Ribosome, Proteasome, Mitochondria, Golgi Vesicle, Golgi Apparatus, Smooth ER, Lysosome, Peroxisome
Mitochondria
***major site of energy metabolism
generate ATP, contain their own DNA
Nucleus
*** information storage and retrieval
contains all information needed for DNA replication
Ribosomes
***site of protein synthesis
made of specialized RNA and proteins
site for translation of mRNA
Golgi apparatus
***protein modification, sorting, and export
Proteasome
***degradation of non-functional or mis-folded proteins
Essential for the cell cycle, regulation of gene expression, response to chemical stressors
Lysosomes
***degradation of internal and ingested material
housekeeping and defensive functions (dispose of organelles and protect against invaders)
Plasma Membranes
***defines cell boundary
highly regulated solubility and permeability layer
allows for establishment of concentration gradients
Simple Diffusion
passive, no energy used
*requires concentration gradient
passage of molecules to equalize concentration on each side of the cell membrane
Facilitated Transport
*requires concentration gradient
movement aided by transport proteins
faster than diffusion
Active Transport
requires use of energy
goes against concentration gradients
Primary: ATP hydrolysis occurs during transport events
Symport: both compounds move in the same direction
Antiport: compounds move in opposite direction
Explain the role of energy expenditure in driving processes needed to maintain living systems
Energy must be expended in order to drive processes that maintain homeostasis
The self associating and hydrophobic nature of lipids as a contributor to membrane function
allows the phospholipid layer to exist
