BIO 161 PSU EXAM 1 QUESTIONS AND
ANSWERS A+ GRADED
homeostasis
the body's ability to maintain a constant environment
two types of control systems in the body
negative and positive feedback loops
negative feedback loops
body senses change and reacts to negate or reverse the condition
positive feedback loops
self-amplifying cycles in which an initial change leads to a greater change
four major categories of organic molecules
carbohydrates, lipids, proteins, nucleic acids
monomer
single molecular unit of a polymer
polymer
molecule containing many repeating single molecules (monomers)
three main types of lipids
triglycerides, phospholipids, steroids
function of phospholipids
cell/organelle membranes
composition of phospholipids
fatty acids, phosphate group, glycerol
function of triglyerides
energy storage and insulation
composition of triglycerides
1 glycerol and 3 fatty acids
protein
polymer of amino acid monomer
nucleic acids
function hereditary (DNA) and protein synthesis (RNA)
gene expression
making proteins from our DNA
transcription
makes a working copy of the gene (RNA)
translation
translates nucleotides to amino acids
cytoplasm
-fluid inside cell
-location of many cellular reactions including some with cellular respiration
nucleus
, -location of DNA
-surrounded by nuclear membrane (lipids) that helps regulate transport in and out
endoplasmic reticulum
-made of lipids
-location of translation (protein synthesis) via ribosomes
ribosomes
organelles made of protein and RNA that direct protein synthesis in the cytoplasm
Golgi bodies
-stacks of membranes
-packaging proteins for transport in membrane
vesicles
small membrane sacs that specialize in moving products into, out of, and within a cell
mitochondria
-function in ATP production (cellular respiration)
-have a small piece of circular DNA
--inherited from mom
--mutations can cause diseases
Cytoskeleton
-network of proteins in the cytoplasm
functions of cytoskeleton
-structural support
-tracks for the transport of organelles or vesicles
-important for muscle function
--cytoskeletal proteins (actin) allow for muscle contraction
the plasma membrane
made of phospholipids, cholesterol, and membrane proteins
what causes the plasma membrane to be selectively permeable?
hydrophobic chains
hydrophilic heads
what plays a role in what molecules can easily diffuse across a membrane?
size, polarity, charge
2 types of transport across a cell membrane
active and passive
passive transport
-diffusion (simple or facilitated) is an example of passive transport
-requires a CONCENTRATION GRADIENT
--particles move from high to low concentration
example of facilitated diffusion
channel-mediated transport
leak channels
channels that are always open
gated channels
channels that are only open at certain times
carrier mediated transport
includes facilitated diffusion when solute travels down concentration gradient
--solute must bind to carrier protein (called pumps)
ANSWERS A+ GRADED
homeostasis
the body's ability to maintain a constant environment
two types of control systems in the body
negative and positive feedback loops
negative feedback loops
body senses change and reacts to negate or reverse the condition
positive feedback loops
self-amplifying cycles in which an initial change leads to a greater change
four major categories of organic molecules
carbohydrates, lipids, proteins, nucleic acids
monomer
single molecular unit of a polymer
polymer
molecule containing many repeating single molecules (monomers)
three main types of lipids
triglycerides, phospholipids, steroids
function of phospholipids
cell/organelle membranes
composition of phospholipids
fatty acids, phosphate group, glycerol
function of triglyerides
energy storage and insulation
composition of triglycerides
1 glycerol and 3 fatty acids
protein
polymer of amino acid monomer
nucleic acids
function hereditary (DNA) and protein synthesis (RNA)
gene expression
making proteins from our DNA
transcription
makes a working copy of the gene (RNA)
translation
translates nucleotides to amino acids
cytoplasm
-fluid inside cell
-location of many cellular reactions including some with cellular respiration
nucleus
, -location of DNA
-surrounded by nuclear membrane (lipids) that helps regulate transport in and out
endoplasmic reticulum
-made of lipids
-location of translation (protein synthesis) via ribosomes
ribosomes
organelles made of protein and RNA that direct protein synthesis in the cytoplasm
Golgi bodies
-stacks of membranes
-packaging proteins for transport in membrane
vesicles
small membrane sacs that specialize in moving products into, out of, and within a cell
mitochondria
-function in ATP production (cellular respiration)
-have a small piece of circular DNA
--inherited from mom
--mutations can cause diseases
Cytoskeleton
-network of proteins in the cytoplasm
functions of cytoskeleton
-structural support
-tracks for the transport of organelles or vesicles
-important for muscle function
--cytoskeletal proteins (actin) allow for muscle contraction
the plasma membrane
made of phospholipids, cholesterol, and membrane proteins
what causes the plasma membrane to be selectively permeable?
hydrophobic chains
hydrophilic heads
what plays a role in what molecules can easily diffuse across a membrane?
size, polarity, charge
2 types of transport across a cell membrane
active and passive
passive transport
-diffusion (simple or facilitated) is an example of passive transport
-requires a CONCENTRATION GRADIENT
--particles move from high to low concentration
example of facilitated diffusion
channel-mediated transport
leak channels
channels that are always open
gated channels
channels that are only open at certain times
carrier mediated transport
includes facilitated diffusion when solute travels down concentration gradient
--solute must bind to carrier protein (called pumps)
