1
Q
properties of water
A
- solvent
- metabolite (used during metabolic processes)
- temperature buffer (absorbs heat)
- maintains biological structures
2
Q
electronegativity (EN)
A
tendency of atoms to attract electrons (higher EN = more attraction)
- determines type of bonds b/w atoms
3
Q
intramolecular force
A
force/attraction within molecule (H and O in H2O)
4
Q
intermolecular force
A
force/attraction b/w molecules (2 H2O molecules)
5
Q
ionic bonds
A
- metal + non-metal
- electrons are transferred
- intramolecular force
6
Q
△EN b/w atoms and their bonds
A
△EN>1.7 = ionic
△EN=0.40-1.69 = polar covalent
△EN<0.39 = non-polar covalent
7
Q
polar covalent bonds
A
-nonmetal + nonmetal
- shares electrons unevenly
- results in dipole
- δ- = higher EN, δ+ = lower EN
- intramolecular bond
8
Q
dipoles
A
unequal distribution of charge b/w atoms
- arrow goes towards atoms w/ higher EN in diagram
9
Q
non-polar covalent bonds
A
- nonmetal + nonmetal
- shares electrons evenly
- intramolecular bond
10
Q
properties of non-polar molecules
A
- 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
11
Q
properties of polar molecules
A
- asymmetric
- polar covalent bond
- atoms on central atom are different OR bond angles are different
- central atom may have lone pairs
- dipoles exist
12
Q
what is a pure covalent bond
A
covalent bond existing b/w atoms with the same electronegativities
13
Q
hydrogen bond
A
- intermolecular force (not a bond)
- attraction b/w slightly neg and slightly pos regions of 2 polar molecules
- shown as dotted line on diagram
14
Q
cohesion + surface tension of water
A
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
15
Q
cohesion vs. adhesion
in terms of water
A
water attracting itself vs. water attracting another molecule
16
Q
capillary action
A
- movement of water through narrow space
- adhesion of water on walls of vessel creates an upward force
17
Q
cohesion-tension theory/hypothesis
A
- 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
18
Q
capillary action in soil
A
- capillary action allows soil to retain water as it moves through soil pores
- type of soil affects height of water rise
19
Q
dissolving (water as solvent)
A
- solute molecules separate from each other and are surrounded by water molecules, forming a “hydrogen shell”
20
Q
solvation
A
interaction b/w solvent and dissolved molecules
21
Q
hydrophilic
A
- molecules that attract water
- includes polar molecules and charged ions
- δ+ of water molecule (hydrogen) is attracted to δ- of solute/anion + vv.
22
Q
hydrophobic
A
- molecules that do not attract water
- includes non-polar molecules
- attracted to other hydrophobic molecules
23
Q
water’s role in metabolism
A
- cytosol is 80% water
- contains dissolved salts, fats which are needed by cells
- dissolved enzymes/reactants for rxns
24
Q
catabolic reactions vs. anabolic reactions
A
breaking down larger molecules into smaller ones vs. building larger molecules from smaller ones
25
water's role in plant transport
- dissolves mineral ions + sugars which are transported through xylem + phloem
26
water's role in animal transport
- dissolves solutes (salt, amino acids, proteins, glucose) and transports them through plasma
27
lipoproteins
- since lipids are all hydrophobic, must be coated in proteins and phospholipids to be transported in blood, creating lipoproteins
28
properties of water vs air
- water is more buoyant
- water has higher viscosity
- water has higher thermal conductivity
- water has higher specific heat capacity
29
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
30
cell theory
1. all living things are composed of cells
2. the cell is the basic unit of life
3. all cells come form preexisting cells
31
processes of life in unicellular organisms
homeostasis, metabolism, nutrition, movement, excretion, growth, response to stimuli, reproduction
32
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
33
metabolism in paramecium + chlamydomonas
- sum of all chemical rxns in cell
p: cytoplasm contains enzymes
c: cytoplasm + chloroplasts contain enzymes
34
paramecium
eukaryotic, unicellular organisms that live in aquatic habitants
35
chlamydomonas
unicellular green algae found in wet environments
36
nutrition in paramecium + chlamydomonas
- includes autotrophs + heterotrophs
- obtains energy and matter
p: heterotrophs, eats smaller unicellular organisms
c: autotrophs, photosythesis
37
movement in paramecium + chlamydomonas
- universal feature (sessile: stays in one place, motile: mobile)
p: moves to search for food
c: moves/spins using flagella
38
excretion in paramecium + chlamydomonas
- getting rid of metabolic waste matter
p: excreted through anal pore
c: expels oxygen through diffusion in cell membrane
39
growth in paramecium + chlamydomonas
- must either grow (small->big) or develop (tadpole->frog)
p + c: cell will grow until SA:volume reached
40
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)
41
reproduction in paramecium + chlamydomonas
- sexual/asexual
p +c: divides via mitosis/meiosis
42
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
43
discrepancies in aseptate fungal hyphae
- many nuclei
- no defined cells, continuous structure of "fused" cells
44
discrepancies in skeletal muscle fiber
- many nuclei
- fusion of multiple cells resulting in large cell with many nuclei
- crucial, makes movement smooth
45
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)
46
how does iodine stain
- starches stained brown/black
- glycogen shows red
47
how does methylene blue stain
- nuclei + DNA becomes prominent (darker blue)
48
how does gram stain stain
- classifies bacteria into gram positive and gram negative
49
formula to find FOV under high power
(LP FOV x magnification of LP)/magnification of HP
50
formula to calculate actual size, magnification, and image size
magnification = image size/actual size (M=I/A)
51
fluorescent stains + discovery
- stained antibodies bind to target proteins, allowing us to follow movement of proteins because of immunofluorescence
- generates bright images
- first developed in 1942
- Fry+ Edidin discovered proteins in cell membrane can move around in 1970, supporting fluid mosaic model
52
freeze-fracture + discovery
- rapid freezing then fracturing of electrons along weak point, etched w/ coating creating replica of surfaces
- electron microscope preparation technique
- developed in 1960s
- discovered integral proteins scatted through centre of membranes, supports fluid mosaic model
53
cryogenic election microscopy + discovery
- molecule of interest is frozen, bombarded w/ beam of electrons--> computer analyzes patterns and produces image
- can see molecules at near atomic-level resolution
- developed in 1980s
- used during COVID to investigate spike proteins, helped develop pharmaceutical drugs to inhibit protein
54
phospholipid structure
- hydrophilic head (containing phosphorus) attracted to outside water
- hydrophobic tail (containing fatty acids) attracts other tails
- amphipathic --> single molecule containing both hydrophilic and hydrophobic parts
- creates selectively permeable plasma membrane
55
what's a phospholipid
- major component of cell membrane
- synthesized by smooth ER
56
importance of cellular membranes
- unique cellular chemistry (accumulation of higher concentration of nutrients/ions inside cell compared to outside)
- compartmentalization within cell (harmful substances can be isolated)
57
why is it called the fluid mosaic model
fluid: components can rotate, move laterally, "flip flop" (rare)
mosaic: refers to many proteins, lipids, carbs involved in creating structure
58
membrane asymmetry
refers to how inside of membrane and outside of membrane look different
59
extracellular vs. intracellular
facing outside of cell vs facing inside of cell
60
glycoprotein + glycolipid
"tree" of carbohydrates (oligosaccharides) residing on a protein/lipid
- typically 3-10 units long, only on extracellular surface
- can distinguish own cells from invaders (ex. blood antigens distinguishes ABO blood types)
- can adhere to neighboring cells (glycoproteins/lipids adhere to each other preventing cells from falling apart)
61
integral protein
large protein that often spans through entire depth of phospholipid bilayer
- spans through: transmembrane
- doesn't span through: integral monotopic
62
cholesterol in fluid mosaic model
chain of hexagons inside bilayer
63
peripheral protein
circular blob that resides on single side of bilayer
- never goes completely through
- often temporary
64
diffusion through cell membrane
- not selective
- follows concentration gradient
- passive (doesn't require energy)
65
variables determining permeability in cell membrane
1. particle size (permeable to small molecules, not to large ones)
2. hydrophilic/hydrophobic (permeable to hydrophobic particles, sometimes permeable to small hydrophilic polar molecules, not permeable to ions, large uncharged polar molecules ex. amino acids, glucose)
66
non-polar steroids + phospholipid bilayer
- a group of lipids with 4 rings of carbon atoms, 17 total carbon atoms (ex. estrogen)
- can diffuse directly through membrane because they are non-polar, hydrophobic
67
what are the functions of membrane bound proteins
enzymatic activity, receptors, transport, recognition, adhesion, anchorage
68
membrane bound proteins + enzymatic activity
- many proteins are enzymes, acts like catalyst for chemical reactions
69
membrane bound proteins + receptors
- chemical receptor proteins (chemoreceptors), embedded in membrane and sends signals (ex. hormone and sensory receptors)
70
membrane bound proteins + anchorage
- releases materials into extracellular space, creating extracellular matrix (ECM)
- provides support, segregates tissues, regulates intercellular communication
71
channel proteins
- type of transmembrane transport protein
(makes hydrophilic tunnel creating facilitated diffusion, allowing wanted molecules to pass through, typically inorganic ions)
- passive movement, moves with concentration gradient
72
aquaporins
- channel protein transporting water
- water molecules move through single file, preventing other molecules from entering
- cells that absorb water often have many of these
- passive movement, works with osmosis
73
pump proteins
- type of transport protein
- when molecule/ion enters, ATP triggers a shape change in protein allowing it to exit/enter
- actively moves solutes across membrane (needs ATP energy), moves against concentration gradient
74
ATP energy
adenosine triphosphate
- "energy currency" of a cell
- produced by aerobic cellular respiration
75
osmosis
**passive net movement** of water molecules moving from low solute concentration to high solute concentration through **selectively permeable membrane**
76
osmolarity
measure of concentration of solute in/out of cell/fluid
77
how do plants use osmolarity
- roots pump solute into extracellular space near surface of roots
- creates high [solute] in roots, low [solute] outside of roots
- causes osmotic pressure, osmosis causes water to go into roots, pushes up xylem
78
standard deviation
measure of range of variation
- SD large = large variation
- normal distribution: 68% within 1 standard deviation, 95% within 2
79
formula for standard error of mean
SE = standard deviation/√# of samples
- measures reliability of mean of sample at estimating mean of entire population
80
hypertonic
higher solute concentration outside of cell
81
hypotonic
when solute concentration is lower outside of cell
82
isotonic
when solute concentration is equal in and out of cell
83
pros and cons of cell wall
pros: stronger than steel, size doesn't fluctuate much, solid
cons: cannot move as easily, freely permeable
84
animal cell in 3 osmotic conditions
hypertonic: cell shrivels up (water loss)
isotonic: no change, cell stays healthy
hypotonic: cell swells from water, bursts
85
plant cell in 3 osmotic conditions
hypertonic: leaf body shrinks. pulls away from cell wall (wilting)
isotonic: no change, stays healthy
hypotonic: stiffens from extra water, retains shape because of cell wall
86
medical applications for isotonic solutions
- giving fluids trough IV
- rinse wounds
- keep skin moist for skin graphs
- eyedrops
- frozen solutions can help freeze organs for transport
87
zygote
- when sperm+egg cell fuse
- single cell organism that divides by mitosis to form embryo full of genetically identical cells
88
gene expression
- allows info in genes to become a function
- often DNA (gene) forms RNA, then is translated into a protein
89
how does differentiation during embryonic development work
- positions of cells within embryo determine how they will differentiate
- cells near outside are exposed to more morphogens (signalling molecules like retanoic acid) than ones in the middle, turning genes on and off
90
stem cell niches
- many tissues/organs have multipotent adult stem cell that living in the stem cell niches (can remain dormant here for years)
- receives physical and chemical signals - when they are needed, conditions inside stem cell niches allow them to divide and differentiate rapidly
91
stem cell niches in bone marrow
- RBC, WBC, platelets originate from hematopoietic stem cell niche
- provides protection and physical+chemical signals
92
totipotent stem cells
- entirely potential, can become any body cell
- ex. zygote, plant zygote
93
pluripotent stem cells
- many potentials, can become any body cell (excluding placenta)
- ex. embryo
94
multipotent stem cells
- multiple potentials, can become multiple different kinds of related cells
- ex. tissue stem cells, progenitor cells
95
unipotent cell
the final cell type after differentiation, will never become another cell type
96
importance of cell specialization
allows cell to perform tasks efficiently (ex. creating different proteins for different needs)
97
surface area: volume ratio
- cells require constant removal of waste from metabolism, if SA if too small, this process happens too slowly, cell may overheat
- rate of molecule movement in/out of cell depends on surface area
98
implications of cell theory
- can trace origin of all cells in body back to single cell produced by zygote
- all cells can be traced back billions of years to LUCA (last universal common ancestor)
- first ever cell must have come from non-living material
99
how are sister chromatids held together
1. centromere adheres middle of sister chromatids together, site of kinetochore and microtubule attachment
2. cohesion (protein complex) hold sister chromatids side by side, established in interphase, removed during anaphase
100
DNA packaging
- double helix made of 2 antiparallel strands of nucleotides
- linking by hydrogen bonding b/w complementary base pairing
- in eukaryotes, DNA wraps around histone proteins, forming nucleosomes which stack together forming chromatins which condense during mitosis creating chromosome
101
DNA condensing
- during interphase, chromatin are present as they're more accessible for enzymes
- prophase: chromatin condenses by "supercoiling" becoming chromosome (easier to transport)
102
kinetochore
protein complex that assembles at centromere
- each sister chromatid has own, links chromatids to microtubules
103
movement of chromosomes
anaphase: sister chromatids separate form each other, motor proteins of kinetochores move separated chromatids along microtubules to poles of cell
104
microtubules
long polymers of protein called tubulin that form mitotic spindle (part of cytoskeleton)
105
anucleate
lacking a nucleus
106
simple definition of mitosis
single nuclear division resulting in 2 genetically identical nuclei
107
simple definition of meiosis
2 nuclear division resulting in 4 genetically diverse daughter cells w/ half as many chromosomes as parent cell
108
cytokinesis in plant cell
- golgi buds off vesicles, move towards cell equator
- vesicles fuse to create cell plate to separate daughter cells
- daughter cells release cellulose through exocytosis at cell plate, creating a new cell wall
109
exocytosis
process of moving large molecules out of cell, to exterior
110
cytokinesis in animals cells
- contractile proteins called actin+myosin form rings at equator, contract to form cleavage furrow
- cleavage furrow continues pinching until cells split
111
equal cytokinesis
- cytoplasm + organelles split equally
- daughter cells must receive all organelles
- some organelles are disassembled then reformed after division, some go through own division process
112
unequal cytokinesis
- daughter cell receives small portion of cytoplasm
- initially remains attached to parent cell, eventually separates into own cell
- process done by yeast
113
pili
- hair-like surface of many bacteria nad archaea
- allows cell to attach to surfaces, swap DNA w others, harpoon DNA into environment
- present in prokaryotic cells
114
plasmid
- extra circular DNA not associated with proteins
- contains genes for antibiotic resistance
- present in prokaryotic cells
115
transcription
to make RNA copies of genes
116
translation
synthesize of proteins for cellular functions
117
ribosomes
- 2 subunits
- synthesizes polypeptides (amino acid chains of tubulin) during translation
118
transport vs secretory vesicles
transports molecules by budding off one organelle and fusing onto another vs. secretes molecules + phospholipids into cell membrance
119
phagocytes
- immune cells that engulfs unwanted materials
- many in lysosomes
120
endosymbiosis theory
- 2 organisms that live one inside the other
- ex. eukaryotic cells ingests respiratory prokaryotic cells for nutrition, but instead pf digesting it, it's kept --> eukaryotic cell incorporates it into life cycle - these cells evolved into modern mitochondria cells
121
centrioles
- composed of 9 groups of 3 microtubules , has radial symmetry
- arranges mitotic spindle during cell division, anchors points of microtubules, cilia, flagella
122
cilia vs flagella
many short protrusions beating in unison vs less longer protrusions moving independently
123
holozoic
gets nutrition from ingesting complex organic matter (ex. animalia)
124
saprotroph
organism that derives nourishment from decaying organic matter (ex. fungi)
125
how cell size and specialization help white blood cells
- size when inactive: 10μm, when active: 30μm
- job is to produce + secrete antibodies
- during infection, size increases because of increase of rough ER + golgi apparatus (both used to secrete antibody proteins)
126
____ is not found in multicellular plants
cilia
