Chapter 8: Dynamic Cells Flashcards
what are the major elements in cells?
- carbon
- hydrogen
- oxygen
- nitrogen
what are the organic compounds in cells?
- lipids
- carbohydrates
- proteins
- nucleic acid
what is a MAJOR compound in both plants and animal cells?
water, solvent for all biological reactions
trace elements?
are substances that are found in small amounts for the cell’s health, example: Mg, Zn, Mn, Fe
what does the cell membrance?
important for maintaining equilibrium inside cell
what is selectively permeable?
allows some cells to pass and keeps away other non-wanted cells
what does the membrane consist of?
phospholipid bilayer
what are suspended in the phospholipid bilayer?
proteins are suspended in:
- out or in the membrane
- some run through the membrane
- some proteins are suspended on the surface with glycoproteins on it
what are some particles that can enter/exit the membrane?
- ions
- molecules
- mirco-organisms
what is brownian motion?
particles are in a constant and random motion. helps with transportation
what is concentration gradient?
moles move from high to low concentration, follows the flow to move past the membrane
what is equilibrium?
when molecules are equally distributed on both sides of the membrane
what is passive transports?
the movement of cells following concentration gradient without energy (ATP)
types of passive transportation
- diffusion
- facilitated diffusion
- osmosis
all moves with concentration gradient without energy
what is simple diffusion ?
particles move down the concentration gradient to reach equilibrium (from high concentration to low)
what is facilitated diffusion?
use of transport proteins to help particles with diffusion across the membrane, used for molecules too big or charged
what is osmosis?
when highly solvent particles move from semi-permeable membrane in order to be diluted by water
types of facilitated diffusion
- carrier proteins: transports large molecules in changing its shape
- channel proteins: transports charged molecules in a tunnel like pore
hypotonic ?
more water, less solvent (swells)
hypertonic?
more solvent, less of water (shrink)
isotonic ?
equal concentration
what causes rate of diffusion to be higher?
- added heat
- increased movement in molecules
what is active transport?
uses energy (ATP) to move molecules against the current and could use protein carriers (moves from low to high)
reasons why cells use active transportation?
- plant cells root take in minerals from surround soils
- animals cells remove waste
what is endocytosis?
takes in materials or fluids inside the membrane
types endocytosis?
a) phagocytosis: eats materials and foods
b) pinocytosis: drinks fluid and water
c) receptor-mediated: receptor protrudes out of the membrane and detects specific molecules (take in molecules such as cholesterol)
what is exocytosis?
allows materials stored in vesicles and vacuoles to exit cell
(fuses with membrane and stored contents are released)
what is a unicellular ?
single cells that are more efficient, but takes time to absorb the nutrients
what is particle diffusion?
NO ENEGRY NEEDED
once substance is inside the cell, rate of diffusion is slow and inefficient due to the weak pull
why are larger cells inefficient?
the larger cell, the more space there is that a particle needs to go to a certain area ( less efficient at getting nutrients)
surface area to volume ratio
surface area = cell membrane
volume = cell contents
why does surface area to volume ratio relate with diffusion rate?
rate of diffusion depends on the surface area to volume ratio
- smaller cells have bigger surface area and less volume meaning it more efficient in exchanging material unlike the larger cells
why do cells divide?
cells grow faster in volume than surface area causing them to divide
why are larger cells bad?
larger cells have a lower surface area to volume ratio, causing them to be starved or poisoned (limits growing)
why are multicellular organisms better?
divides up life functions and having a higher rate of survival than unicellular due to cell division (can also increase in size without a limit)
