unit test #1 Flashcards
properties of water
- solvent
- metabolite (used during metabolic processes)
- temperature buffer (absorbs heat)
- maintains biological structures
electronegativity (EN)
tendency of atoms to attract electrons (higher EN = more attraction)
- determines type of bonds b/w atoms
intramolecular force
force/attraction within molecule (H and O in H2O)
intermolecular force
force/attraction b/w molecules (2 H2O molecules)
ionic bonds
- metal + non-metal
- electrons are transferred
- intramolecular force
△EN b/w atoms and their bonds
△EN>1.7 = ionic
△EN=0.40-1.69 = polar covalent
△EN<0.39 = non-polar covalent
polar covalent bonds
-nonmetal + nonmetal
- shares electrons unevenly
- results in dipole
- δ- = higher EN, δ+ = lower EN
- intramolecular bond
dipoles
unequal distribution of charge b/w atoms
- arrow goes towards atoms w/ higher EN in diagram
non-polar covalent bonds
- nonmetal + nonmetal
- shares electrons evenly
- intramolecular bond
properties of non-polar molecules
- symmetrical
- “pure” covalent bonds
- atoms bonded to central atom must be the same AND bond angles must be the same
- no lone pairs on central atom
- no dipoles/have been cancelled out
properties of polar molecules
- asymmetric
- polar covalent bond
- atoms on central atom are different OR bond angles are different
- central atom may have lone pairs
- dipoles exist
pure covalent bond
covalent bond existing b/w atoms with the same electronegativities
hydrogen bond
- intermolecular force (not a bond)
- attraction b/w slightly neg and slightly pos regions of 2 polar molecules
- shown as dotted line on diagram
cohesion + surface tension of water
cohesion of molecules (thanks to hydrogen bonds) allows water to resist external forces
- molecules of water are more attracted to other H2O molecules rather than air
cohesion vs. adhesion
water attracting itself vs. water attracting another molecule
capillary action
- movement of water through narrow space
- adhesion of water on walls of vessel creates an upward force
cohesion-tension theory/hypothesis
- widely accepted model of water movement in plants
1. transpiration (evaporation), occurs in stomata and created tension (negative pressure)
2. tension from transpiration “pulls” water up xylem upwards
3. cohesion, water moves like a “chain” as water is pulled out of stomata
4. adhesion, water creates hydrogen bonds to xylem walls, allowing it to “crawl” up
capillary action in soil
- capillary action allows soil to retain water as it moves through soil pores
- type of soil affects height of water rise
dissolving (water as solvent)
- solute molecules separate from each other and are surrounded by water molecules, forming a “hydrogen shell”
solvation
interaction b/w solvent and dissolved molecules
hydrophilic
- molecules that attract water
- includes polar molecules and charged ions
- δ+ of water molecule (hydrogen) is attracted to δ- of solute/anion + vv.
hydrophobic
- molecules that do not attract water
- includes non-polar molecules
- attracted to other hydrophobic molecules
water’s role in metabolism
- cytosol is 80% water
- contains dissolved salts, fats which are needed by cells
- dissolved enzymes/reactants for rxns
catabolic reactions vs. anabolic reactions
breaking down larger molecules into smaller ones vs. building larger molecules from smaller ones
water’s role in plant transport
- dissolves mineral ions + sugars which are transported through xylem + phloem
water’s role in animal transport
- dissolves solutes (salt, amino acids, proteins, glucose) and transports them through plasma
lipoproteins
- since lipids are all hydrophobic, must be coated in proteins and phospholipids to be transported in blood, creating lipoproteins
properties of water vs air
- water is more buoyant
- water has higher viscosity
- water has higher thermal conductivity
- water has higher specific heat capacity
specific heat capacity + water
amount of heat needed to raise 1g of material by 1C
- water has highest SHC out of all liquids, cause by all the hydrogen bonds
cell theory
- all living things are composed of cells
- the cell is the basic unit of life
- all cells come form preexisting cells
processes of life in unicellular organisms
homeostasis, metabolism, nutrition, movement, excretion, growth, response to stimuli, reproduction
homeostasis in paramecium + chlamydomonas
- keeps stable internal environment despite external factors
p + c - pair of vacuoles that change depending on amount of water in cell
metabolism in paramecium + chlamydomonas
- sum of all chemical rxns in cell
p: cytoplasm contains enzymes
c: cytoplasm + chloroplasts contain enzymes
paramecium
eukaryotic, unicellular organisms that live in aquatic habitants
chlamydomonas
unicellular green algae found in wet environments
nutrition in paramecium + chlamydomonas
- includes autotrophs + heterotrophs
- obtains energy and matter
p: heterotrophs, eats smaller unicellular organisms
c: autotrophs, photosythesis
movement in paramecium + chlamydomonas
- universal feature (sessile: stays in one place, motile: mobile)
p: moves to search for food
c: moves/spins using flagella
excretion in paramecium + chlamydomonas
- getting rid of metabolic waste matter
p: excreted through anal pore
c: expels oxygen through diffusion in cell membrane
growth in paramecium + chlamydomonas
- must either grow (small->big) or develop (tadpole->frog)
p + c: cell will grow until SA:volume reached
response to stimuli in paramecium + chlamydomonas
- recognize + respond to environmental factors
p: moves differ to adapt to environment
c: has light sensitive light spot (to find light for photosynthesis)
reproduction in paramecium + chlamydomonas
- sexual/asexual
p +c: divides via mitosis/meiosis
discrepancies in red blood cells
- no nucleus
- as cell matures, discards nucleus + mitochondria
- SA:V ratio increase because of smaller size
- no nucleus = no energy produced
discrepancies in aseptate fungal hyphae
- many nuclei
- no defined cells, continuous structure of “fused” cells
discrepancies in skeletal muscle fiber
- many nuclei
- fusion of multiple cells resulting in large cell with many nuclei
- crucial, makes movement smooth
discrepancies in phloem sieve tube element
- no nucleus or many other organelles
- basically just cytoplasm to transport nutrients
- must have companion cell to keep alive(sends energy across membranes)
how does iodine stain
- starches stained brown/black
- glycogen shows red
how does methylene blue stain
- nuclei + DNA becomes prominent (darker blue)
how does gram stain stain
- classifies bacteria into gram positive and gram negative
formula to find FOV under high power
(LP FOV x magnification of LP)/magnification of HP
formula to calculate actual size, magnification, and image size
magnification = image size/actual size (M=I/A)