final exam Flashcards
What is the chemical level of organization?
atoms that combine to form molecules & macromolecules
What is the cellular level of organization?
organelles, atoms, ions, & molecules become organized into cells (some contain a nucleus)
What is the tissue level of organization?
similar cells from similar origins work together as a unit
What is the organ level of organization?
2 or more tissues that work together for the same function
What is the organ system level of organization?
2 or more organs work together
What is the organismal level of organization?
all systems working together
What are the levels of organization?
chemical, cellular, tissue, organ, organ system, & organismal
What is homeostasis?
the body tries to keep everything constant & in the same state
What are the 4 types of tissues?
connective, epithelial, muscular, & nervous
What are protons?
found in the nucleus of an atom; carry a positive electrical charge
What are neutrons?
found in the nucleus of an atom; carry no electrical charge
What are electrons?
found in the shell of an atom; carry a negative electrical charge
When are atoms most stable?
when the outer shell is filled to the maximum; shells must be filled in order to
What is ionic bond formation?
a transfer; an electron moves from one atom to another, forming charged particles called ions
What is covalent bond formation?
a pair of electrons is shared; the 2 types are polar & non-polar
What are polar covalent bonds?
unequal sharing of a pair of electrons
What are non-polar covalent bonds?
equal sharing of a pair of electrons
What are hydrogen bonds?
weak associations between adjacent polar molecules
What do hydrogen bonds result in?
surface tension, capillary action, frost formation, & protein structure
How do hydrogen bonds affect protein structure?
they give the proteins a precise 3-D shape
What are carbohydrates?
commonly called sugars & starches; they contain carbon, hydrogen, & oxygen in the ratio 1:2:1 & have the chemical formula (CH2O)n
What do carbohydrates do?
they serve a structural purpose in our cells & are broken down to provide our cells with the energy required to carry out daily functions
What are lipids?
non-polar molecules that are hydrophobic; they are commonly called fats & oils
What are phospholipids?
unique hybrid molecules that contain 2 non-polar hydrophobic carbon chains (tails) & 1 hydrophilic phosphate molecule (head)
Why are phospholipids useful?
they form integral parts of cell membranes
What are proteins?
big molecules used as enzymes, energy sources, & structural components in the cell; they are made of subunits called amino acids
What are cholesterol units?
they hold the phospholipid membrane together & prevent unraveling (similar to staples)
What purpose do 3-D proteins serve in our cell membranes?
they are scattered throughout to serve as channels to enter/exit; some have branched carbs that serve as receptors
