seven tenets of the nature of science
1. science demands evidence
2. scientific ideas are durable
3. science avoids bias
4. the natural world is understandable
5. scientific ideas are subject to change
6. science is imaginative
7. science is a social activity
observation
using your 5 senses to gather information
inference
an attempt to explain/interpret things you observe
(can change with new information)
data
facts & stats collected
qualitative data
data that is collected using words (adjectives)
quantitative data
data that is collected using numbers (amounts, temperature, etc.)
variables
factors in an experiment
independent variable
variable changed by the scientist; what you are testing
dependent variable
response to the IV that can be observed and measured
control
factor in an experiment that a scientist purposely keeps the same
constant
a variable that is NOT changed
modeling
constructing a representation of an object
scientific law
a fact of nature
doesn't offer an explanition
driving question
an open ended question that sets the stage for the project by creating interest and curiosity
hypothesis
a tentative explanation that can be tested and is based on observations
theory
explanation of a natural phenomenon
spontaneous generation
the supposed production of living organisms from nonliving matter
Redi
-meat and maggots
-spontaneous generation is NOT true
-IV = flask (covered vs. uncovered)
Needham
-discounted Redi's conclusion
-boil gravy (short time)
-IV = flask (covered vs. uncovered)
Spallanzani
-actually boiled gravy
-IV = flask (covered vs. uncovered)
Pasteur
-disproved spontaneous generation
-s curve
-IV = flask (s-curve vs. broken)
sampling
scientific technique of using a subset to represent an entire population
-ology
(ex. biology, zoology, etc.)
study of
Cyto-
(ex. cytoplasm)
cell
Nuc-
(ex. nucleus)
center
Pro-
(ex. prokaryote)
before
Eu-
(ex. eukaryotic)
true
Mono-
(ex. monomer)
one, single
Poly-
(ex. polymer)
many, much
Hydro-
(ex. hydrogen, hydrolysis, hydrophobic, etc.)
water
-ose
(ex. glucose, lactose, fructose, etc.)
sugar
Bi-/Di-
(ex. binary fission, binomial, disaccharide, etc.)
two
Macro-
(ex. macromolecules)
large, big
Lip-/Lipo-
(ex. lipids)
fat, fatty
Exo-
(ex. exocytosis)
out
Endo-
(ex. endocytosis)
inside, within
-ase
(ex. lactase)
enzyme
Co-
(ex. coenzyme)
together
A-
(ex. abiotic)
not, without, lacking
Ad-
(ex. adhesion)
to, towards, stick
Anti-
(ex. antibiotic)
against, opposite
Bio-
(ex. biology)
life, living
make up 96% (or more)of humans
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur
compound
pure substances that are composed of atoms of 2 or more different elements chemically combined
proton
positively charges
in nucleus
electron
negatively charged
neutron
neutral charge
in nucleus
ionic bonds
atoms give up (lose) or gain electron and are attracted to each other
covalent bonds
atoms share electrons to get a full valence shell
hydrogen bonds
bonds on H2O molecule to another H2O molecule
adhesion
2 DIFFERENT molecules stick togeter
cohesion
2 of the SAME molecules stick together
surface tension
adhesion + cohesion
capillary action
water molecules cling to each other and other substances
polarity
a molecule that has a slightly negative and a slightly positive charge
electronegativity
when the number of protons is higher in the Oxygen then the Hydrogen so the higher number of protons pull/attract the electrons
(create a partial charge)
pH below 7 is __________
acidic
pH above 7 is __________
basic
what is the pH of pure water?
7
examples of carbohydrates
starch
glucose
fructose
lactose
glycogen
carbohydrates are composed of...
carbon
hydrogen
oxygen
identifying features of carbohydrates
2 H atoms for every 1 O atom
monomer of carbohydrates
monosaccharides
are carbohydrates soluble in water
yes (very soluble)
functions of carbohydrates
provide short term energy
spare use of proteins
breakdown fatty acids
structural support
flavor
dietary fiber
carbohydrates: name ends in
-ose
carbohydrates: key points
monomers = exactly identical
examples of proteins
amino acids
enzymes
proteins are composed of....
carbon
hydrogen
nitrogen
oxygen
identifying features of proteins
NH2 amino group
carboxyl group
central C
single H
R-group
monomer of proteins
amino acids
are proteins soluble in water?
yes
functions of proteins
structural support
muscle contraction
transportation
immunity
enzymes
proteins: name ends in...
-ase
proteins: key points
joined by peptide bond
examples of lipids
fats
oils
steroids
waxes
triglycerides
lipids are composed of...
carbon
hydrogen
oxygen
identifying features of lipids
H:O ratio much greater than 2:1
monomer of lipids
glycerol
fatty acids
are lipids soluble in water?
no
functions of lipids
long term energy storage
insulation
protective covering
lipids: key points
saturated
unsaturated
polysaturated
examples of nucleic acids
DNA
RNA
nucleic acids are composed of...
carbon
hydrogen
oxygen
nitrogen
phosphorus
identifying features of nucleic acids
5C sugar
phosphate group
N base
monomer of nucleic acids
nucleotides
are nucleic acids soluble in water?
yes
functions of nucleic acids
store info in the cell
characteristics of life
Grow & develop
Reproduce
Adapt & respond to environment
Cells
Energy
Robert Hooke
used microscope to examine cork
saw �small boxes�/cells
Van Leeuwenhook
1st to view living cells
used simple handheld microscope
viewed pond water and teeth scrapings
microscope maker
Schleiden
all plants were made of cells
co-founder of cell theory
botanist
Schwann
all animals were made of cells
co-founder of cell theory
zoologist
Virchow
observed cells dividing
all cells come from pre-existing cells
Cell Theory
1. all living things are made of cells
2. cells are the basic unit of structure/function of living things
3. all cells are produced from existing cells
unicellular
composed of one cell
multicellular
composed of many cells that may organize into tissues
organizational levels of life
1. cells (life starts here)
2. tissues (similar cells working together)
3. organs (different tissues working together)
4. organ system (different organs working together)
5. organisms
prokaryote
1. simplest type of cell
2. lacks a nucleus & membrane bound organelles
3. DNA floats in cytoplasm
4. archaeabacteria & eubacteria
eukaryote
1. more complex cells
2. HAS a nucleus & membrane bound organelles
3. includes protists, fungi, plants, and animals
cell membrane
regulates what enters/exits the cell
(composed of lipids)
cell wall
provides support/protection in PLANT CELLS
centrioles
guide cell division in ANIMAL CELLS
chloroplasts
convert energy from sunlight into a form that PLANT CELLS can use
(photosynthesis)
chromotin
genetic material; DNA + the histone protein it coils around
cytoplasm
gelatinous material outside of the nucleus
holds organelles in place
cytokeleten
protein filaments that move things within the cell
helps cell to maintain its shape
microfillaments
actin; threadlike; movement of the cell
microtubles
tubulin; hollow; guide centrioles during cell division
endoplasmic reticulum
assembles portions of cell membrane
assembles proteins
(rough or smooth)
golgi body
modify, sort, and package proteins
lysosomes
enzyme filled clean-up organelles
brake down material
mitochondria
convert chemical energy from food to a form the cell can use
both plant and animal cells
(cellular respiration)
nucleus
contains DNA
control center of the cell
nucleous
small, dense region of the nucleus
nuclear envalope
surrounds & encloses the nucleus
ribosomes
assemble proteins
vaculoe
store water, salts, proteins, and carbohydrates
structure of cell membrane
-POLAR phosphate head --- hydrophillic
-NONPOLAR fatty acid tails --- hydrophobic
-proteins embedded in membrane
selectively permeable
allows some molecules in and keeps others out
passive transport
cell doesn't use energy
types of passive transport
diffusion
facilitated diffusion
osmosis
active transport
cell does use energy
types of active transport
protein pumps
endocytosis
exocytosis
high to low concentration
passive transport
diffusion
random movement of particles for H->L
facilitative diffusion
diffusion through transport proteins
osmosis
diffusion of water
low to high concentration
active transport
protein pump
transport proteins that require energy to work
endocytosis
taking bulky material into a cell
cell eating - phagocytosis
cell drinking - pinocytosis
exocytosis
forces material out of cell in bulk
hypotonic solution
low solute; high water
result: water moves from the solution to inside the cell
cell swells and bursts open (cytolysis)
hypertonic solution
high solute; low water
result: water moves from inside the cell into the solution
cell shrinks (plasmolysis)
isotonic solution
concentration of solutes in the solution is equal to the concentration of solutes inside the cell
fluid mosaic model
explains how the membrane is a mixture of phospholipids, cholesterol, & proteins and is kept ordered by hydrophobic forces
purpose of photosynthesis
to turn light energy into chemical energy (glucose)
energy capture
purpose of cellular respiration
break down food into energy (ATP)
energy release
photosynthesis reactants
carbon dioxide & H2O
cellular respiration reactants
glucose & oxygen
photosynthesis products
glucose & oxygen (byproduct)
cellular respiration products
carbon dioxide, H2O, and energy
photosynthesis formula
cellular respiration formula
photosynthesis steps
1. light reaction
2. dark reaction/Calvin Cycle
cellular respiration steps
1. glycolysis
2. Krebs Cycle
3. electron transport chain
where does photosynthesis take place?
chloroplast
where does the light reaction (photosynthesis) take place?
thylakoid
where does the calvin cycle (photosynthesis) take place?
stroma
where does cellular respiration take place?
mitochondria
where does glycolysis (cellular respiration) take place?
cytoplasm
where does the krebs cycle (cellular respiration) take place?
matrix
where does the ETC (cellular respiration) take place?
mitochondria inner membrane
who performs photosynthesis?
autotrophs (plants)
who performs cellular respiration?
all organisms
autotrophs
producers
make their own food
heterotrophs
consumers
obtain energy from consuming food
what does ATP consist of?
adnenine
ribose (5-carbon sugar)
3 phosphate group
how many phosphate groups does ADP have?
2
the main pigment in plants is _______________
chlorophyll
chlorophyll absorbs light well in which regions of the visible spectrum?
blue-violet and red regions
thylakoid
saclike photosynthetic membranes
steps of the Calvin Cycle
1. fixation
2. reduction
3. regeneration
glycolysis
breaks down glucose to produce pyruvate
takes place in cytoplasm
anaerobic (doesn't require energy)
krebs cycle
produces: ATP, NADH, FADH2, CO2
aerobic (requires energy)
electron transport chain
uses: O2, NADH, FADH2
produces: ATP, water
aerobic (requires energy)
range of ATP produced in cellular respiration
36-38
fermentation (anaerobic respiration)
producing ATP in the absence of oxygen
in cytoplasm
alcoholic fermentation
occurs in yeast
converts pyruvate to carbon dioxide and ethanol
causes bread to rise
lactic acid fermentation
occurs in muscle cells
converts pyruvate to lactic acid
causes muscle fatigye
what denatures enzymes?
changes in temperature and pH