Homeostasis, Cell Structure & Function Flashcards
How does the phospholid bilayer keep internal and external environments separate?
The polar heads(doesn’t dissolve in liquid) is facing outwards, and non-polar(does dissolve in liquid) tails face inward.
Which kind of molecule passes through the cell membrane easier? Which doesn’t?
Small, uncharged molecules pass through the cell membrane easier than larger, charged molecules.
Define homeostasis.
An organisms ability to maintain its balance in its internal environment.
What are the traits of a prokaryotic cell?
Tend to be smaller and simpler, don’t contain a nucleus or other organelles.
What are the traits of an eukaryotic cell?
Tend to be larger and complex, contains nucleus and other organelles.
What are the three principles of the cell theory?
All living organisms are composed of one of more cells, cells are the basic unit of structure and organization of all living organisms, cells arise only from previously existing cells.
Explain the endosymbiont theory.
Symbiotic relationship formed between two prokaryotic cells, one of which lived inside the other, this led to the cells becoming one.
What is selective permeability?
The membranes ability to choose what goes in and out of the cell.
Describe the conditions polar and non-polar substances dissolve in.
Polar substances dissolve in polar and non-polar dissolves in non-polar.
Define the role of transport
proteins.
Transport proteins move substances that are needed or waste materials through the plasma membrane.
What is the purpose of an endoplasmic reticulum?
ER serves as the site for protein and lipid synthesis.
What is the semifluid material the plasma membrane is surrounded by?
Cytoplasm
What is a cytoskeleton?
long, thing fibers that form a framework for the cell
What are two parts of cytoskeleton?
Microtubules and Microfilaments
What are ribosomes?
Organelles that manufacture proteins.
