midterm 2 Flashcards
diffusion
movement of molecules from areas of high concentration to low concentration
facilitated diffusion
allows the passage of molecules/ ions with their concentration gradient
- doesn’t require energy
active transport
transports ions and molecules against their concentration gradient
- requires energy
eukaryotes
- have membrane bound organelles
- have nucleus
prokaryotes
- no membrane bound organelles
- have ribosomes, DNA, plasma membrane
- no nucleus, mitochondria, endomembrane system
- archaea (extreme environments) and bacteria
plasma membrane
surrounds the cell and controls what goes in and out of the cell
ribosome
makes proteins when mRNA is translated
mitochondria
where cellular respiration occurs in the cell
chloroplasts
site of photosynthesis
cytoskeleton
has an extensive system of fibers, provides cell shape but is also dynamic, forms a layer outside of the cell membrane
- known as the extracellular matrix in animals
viruses
tiny, infectious agents that hijack the host cells’ metabolic machinery
- unable to do anything without a host cell
retroviruses
insert their genetic material into the host’s DNA by using reverse transcriptase to produce DNA from RNA
bacteria
- can live without a host cell
- reproduce asexually
- introduce new DNA into their genome by exchanging plasmids, picking up DNA from the environment, and transfer DNA through viruses
bacteria inhibited by
antibiotics, bacteriophage
potential energy
found in chemical bonds of carbohydrates and lipids, energy storage
- can be increased by the addition of phosphate groups or electrons
enzyme
catalyze reactions by lowering their activation energy
- rate of rxn goes up with temperature until a certain point, then denatures
- optimal pH
cell signaling
used to
- regulate protein synthesis which alters gene expression
- activates proteins already present in cell
signal transduction
used to change the form of a signal
- allows for the amplification of signals by adding phosphate groups
- proteins are activated/inactivated by protein kinases
cellular respiration
allows organisms to convert energy stored inn molecules with high portential energy to energy stored in the bonds of ATP
- as a byproduct, oxygen is consumed while carbon dioxide and water is produced.
fermentation
can occur without oxygen or the electron transport chain, it is extremely inefficient in comparison to aerobic respiration
catabolic pathways
sets of reactions that break down molecules
anabolic pathways
sets of reactions that build molecules
