Ch4&5 Test Study Guide (BRC) Flashcards
magnification
the ratio of the size of the object seen with the microscope to the actual size
(making something small seem large)
resolution
the ability to see two objects separately or distinguish two objects from each other
scanning electron microscope
used to see the details on the surface of the cell
transmission electron microscope
used to see the details of cellular components and internal cellular structures
cell fractionation
separation of cell components; broken apart via centrifugation and organelles are separated by density (more dense= sink, less dense=suspends)
glycocalyx
matrix that aids cells in recognition, contact, and adhesion to other cells
What is Cell Theory?
-cells are basic loving units of organization and function
-cells come from other cells
-cells have a common origin
What is the significance of cell size and surface area?
surface area/volume ratio decreases as the cell increases; small cells have a large ratio which allows for faster diffusion
prokaryote
no nucleus or membrane bound organelles
eukaryote
specialized membrane bound organelles and membrane enclosed nucleus
what are the functions of the cell membrane?
the membrane allows for specialization and simultaneous functioning of cells
What is the path of a protein through the EMS
made/packaged by the rough ER–> transported vesicles carriers protein to cis face entry and fuses to Golgi–> Golgi modifies/packages as it travels through the medial region–> exits trans face through a new vesicle
cilia vs flagella
cilia are small and move substances across cell surfaces while flagella are ling and helps cells move through watery environments
nucleus structure
where rRNA is made, enclosed nuclear envelopes (inner/outer), nuclear pores for transport in/out cell
what is the nucleus’ function
control center
what is the structure of a ribosome?
large & small subunit
what is the structure and functions of the smooth ER?
has no attached ribosomes, synthesizes lipids and breaks down toxins
what is the structure and functions of the rough ER?
has attached ribosomes, synthesizes proteins
what is the structure of the Golgi complex?
flattened membranous sacs (cisternae), cis face, medial region, and trans face
what is the function go the clog complex?
process, sort, and modify proteins (post office)
what is the structure of the mitochondria?
inner/outer membrane, inner fold (cristae), matrix (space between the (cristae)
what is the function of the mitochondria?
produces ATP through aerobic respiration
what is the structure of chloroplast?
inner/outer membrane, thylakoid discs, granum stacks, and stroma
what is the function of chloroplast?
produce glucose through photosynthesis
what is the structure and function of lysosomes?
hydrolytic enzymes; digest bacteria and debris
what is the function of peroxisomes?
metabolize organic molecules
what is the structure and function of vacuoles?
large membrane enclose sacs; plant growth and development
what is the structure and function of microtubules?
hollow, rigid tubes; aid in movement
what is the function fo centrosomes?
aid in cell division
what is the structure of microfilaments?
7nM diameter, solid/flexible, two intertwined chains of beadlike actin molecules
what is the function of microfilaments?
form cell cortex inside plasma membrane, generate movement (actin myosin)
what is the structure and function of intermediate filaments?
10nMin diameter, tough/flexible; strength/stability to cell
what is the fluid mosaic model?
phospholipid molecules behave like liquid crystals and ratite laterally very freely. The molecules are always moving and the configuration of phospholipids is always changing
integral proteins
proteins bound to the cell membrane
transmembrane proteins
integral proteins that extend through the cell membrane
peripheral proteins
attached to one side of the sell membrane
what is selective permeability?
allowing certain substances to pass through the membrane while preventing others
aquaporins
channel proteins that allow the passage of water
diffusion
the flow of a substance from an area of high concentration to an area of low concentration
osmosis
the flow of water from an area of Hugh water concentration to an are of low water concentration
passive transport
transport of molecules across the cell membrane that does not require energy, high concentration to low concentration
active transport
transport of molecules across the cell membrane that relies energy. low concentration to high concentration
example of active transport
NA+/K+ pump the transport of Na+ out of the cell and against the against the gradient and K+ in the cell against the gradient
cotransport
the transport of one substance down its concentration gradient provides energy for the transport of another substance against its gradient
phagocytosis
“cell eating”; the intak of large particles by the cell
what is the structure of the phospholipid bilayer?
has 2 layer of phospholipids; fatty acid tails, and glycerol heads
the role of lipids in membrane fluidity?
in low temps, lipids keep the membrane fluid and flexible and in high temps, lipids act as a buffers and stabilize the hydro carbon chains
what are the function of the lipid bilayer?
boundary, work surface, and store potential energy
what are the functions of membrane proteins?
transport, catalyze enzymatic reactions, anchoring cells, receive, and identification
what is the lipid bilayer permeable to?
small non polar molecules, small polar molecules, and gases (N2, O2, and CO2)
what is a carrier protein?
changes shape to transport substances
what is a channel protein?
opens a gates ot transport substances
what is simple diffusion?
a substance moves directly down a concentration gradient through the membrane
what is facilitated diffusion?
cells expel substances from the cell
what is the structure of desmosomes?
dense materials and protein filaments that are anchored to the intermediate filaments of the cell
where are desmosomes & adhering junctions found?
epithelial cells
what is the stricture of adhering junctions?
cadherins form tight bells around the cell (connected to microfilament)
what is the function of tight junctions?
connect to cell membrane tightly leaving no space
what is the function of a gap junction?
uses connexion molecules to form nervous, cardia, muscle channels
what is the function of plasmodesmatas?
channels pass through walls of neighboring cells, smooth ER of adjacent cells are connected