midterm 1 Flashcards
list the order of life
1- the biosphere
2- ecosystems
3- community
4- populations
5- organisms
6. organs
7. tissues
8. cells
9. organelles
10. molecules
what is the organism’s basic unit of structure and function
cells
what is the smallest unit of organization capable oof preforming all the activities for life
cells
what do all cells have in common
enclosed by a membrane
use dna as genetic information
all life is based on…
heritable information
all forms of life use the same …
genetic code
life require the …
transfer and transformation of energy and matter
energy exchange involves …
transformation of energy from one form to another
structure provides …
clues about function
function provides …
INSIGHT INTO construction
form fits…
function!
structural organization of cells
atoms then molecules then cells q
atoms are the …
foundation
molecules are formed by …
combination of atoms )lipids proteins etc
cells are formed by …
combination of molecules
cells represent…
the lowest structural level capable of preforming life
matter is made up of …
atoms
what was eric betzig involed in
the optical revolution
the optical revolution was invented by
eric betzig
1m=?mm
1000
1mm=?um
1000
1um=?nm
1000
1nm=?pm
1000
o.1nm=? Angstrom
1
water is …
essential for life
cell composition …
70-95%water
carbon-based monlecules= the rest
elements cannot…
be broken down into another substance
how many natural
elements are there
92
how many elements are essential to life
25%
trace elements ….
FE, I, Zn, Cu
__% of living matter is made up from _ elements
96, 4
what are the 4 elements that make up most of living matter
c, o, n, h
atoms are the …
smallest unit of chemical elements
compounds are
molecules made up of two or more elements in a fixed ratio
atoms use what to form molecules and compounds
chemical bonds
what are strong bonds
covalent and ionic bonds
what is covalent bonds
sharing of electrons by two atoms
what type of molecules have covalent bonds
polar and nonpolar molecules
what are weak bonds
hydrogen bonds
nonpolar=
equal sharing of electrons
equal electronegativity
polar=
unequal sharing of electrons
unequal electronegativity
ionic bonds is the
transfer of elevtrons between two atoms
ex of ionic bond
NaCl
what are ionic bonds held by
electrostatic interaction
hydrophilic substances
affinity for water
what do most hydrophilic substances have
polar or ionic bonds that can form hydrogen bonds
hydrophobid substances
repels water
most hydrophobic substances have
nonpolar covalent bond
waxes are …
HYDROPHOBIC
most lipids are
HYDROPHOBIC
in water the two H atoms are ….
covalently bonded to one O atom
cohesion is
the interaction between water molecules
ribosomes have 2 parts name them
large subunit and small subunit
a water molecule can have how many partners…
FOUR
what makes ice less dense than water
lattice structure due to hydrogen bonds
a substance in which another substance dissolves in
solvent
a dissolves substance
solute
mixture of solute and solvent
solution
when an ion dissolves in water what forms q
hydration shell
what is the dominat bonds in lipids
c-c and c-h which are nonpolar with equal sharing of electrons
equation for water dissociation
h20 –> (h+) +(oh-)
what is the sign of pure water
h+=oh-
most biological solutions do not have what?
equal amounts of h+ and oh-
acids…
increase the proton concentration of a solution
bases…
decrease the proton concentration of a solution
what is the change between every ph level
10x
tenfold
buffers…
resist change in ph of a solution
what actions can buffers do?
donat H+ when basic
or donate oh-/or accept h+ when acidic
what is the ph of human blood
7.4
what are the buffers in blood q
carbonic acid and bicarbonate
what is optimal range for blood ph
7.37-7.43
know the equation for carbonic acid
h2co3 <=> (Hco3)- + (H+)
monomer to proteins
amino acids
polymer to proteins
polypeptide
what bonds do polymers have
covalent bonds between monomers
what is a polypeptide
polymer of AAs in specific sequence
what is a protein
one or more polypeptide with specific 3-D conformation
write the sequence of how proteins are made small to large
amino acids, polypeptides, proteins
what is the exception to all enzymes are proteins
rna
what are all proteins made of
amino acids
how many amino acids are there
20
what is the structure of all amino acids
r-group
amino group
carbonxyl group
what part of the amino acid coud be positive inside the cell
the amino group
what gives amino acids its acid part
carboxyl goup can become acid q
what is special about cyesteine (hint: it’s an amino acid)
wealky polar that sometimes is called nonpolar
what reaction creates polypeptides
dehydration reactions join amino acids
what is the amino acid end called of a polypeptide
N terminus
what is the carboxyl end of a polypeptide called
C terminus
what will the ends of a polypetide look like
N terminus (amino group)
C terminus (carboxyl group)
what allows for dehydration
enzymes
what is the primary sequence
amino acid sequence
what are the levels of structure in a SINGLE polypeptide
primary
secondary
tertiary
what is secondary structure
hydrogen bonds by atoms in the polypeptide backbone between nucleotides
what are two types of secondary structure
alpha helix and Beta bleated sheat
what does an alpha helix resemble
coils
what does a beta strand resemble
a pleated sheet
what is a hydrogen bond?
H bonding with another element FROM a different molecule
What is tertiary structure
r- group interaction that determine overall structure of the polypeptide
what are the WEAK types of bonds in tertiary structure
hydrogen
list the cell composition
70-95% water
rest carbon based compounds `
carbon has how many valence electrons
4 meaning it can have 4 other atoms
what are the possible variables of variation in carbon skeletons
- length
- branching
- double bond position
- ring structure
why are functional groups called functional
bc they give their molecule unique properties
what type of bond is in a hydroxyl
polar covalent bond
what is an alternate name for hydroxyl
alcohol
what are ketones
carbonyl groups in the middle of a sugar
what are aldehydes
carbonyl groups at the end of a sugar
what is carboxyl
A WEAK ACID
amino group can be a
base
sulfhydryl group compoud name
thiol
-SH group can form
DISULFIDE bond very strong
-sh is midly
polar
Methyl group compound name
methylated compound
ch3- is very
stable and nonpolar
ch3- can affect
the expression of gene when interect with DNA
phosphate group has a
NEGATIVE CHATGE
Phosphate group is important in
releasing energy
what is VERY important abt dehydration and hydrolysis
NOT SPONTANEOUS
dehydration synthesis
releases a water to join molecules together
what is the simplest carbohydrate
monosaccharides
what is the main fuel of cellular respiration
glucose
what serves as raw material for synthesis of other molecules like amino acids and fatty acids
carbon skeletons
WHAT BOND is FOUND IN A disaccharide
glycosidic linkages
lactose is made of
glucose + galactose
why are people lactose intolerant
they cannot hydrolyze lactose bc lack enzyme lactase
polysaccharides have what two functions
structure and energy storage
what is an example of a polysaccharide structural
cellulose, used in plant cell walls
give all energy storage examples (polysacchardies)
starch in plants
glycogen in animals
which polysaccharides can we not hydrolyze
CELLULOSE
why can cows digest cellulose
they have bacteria in their gut that break it down for them- sometime they cant get antibotics when sick bc it kills the bacteria
what are the three forms of lipids?
fats
phospjolipids
steriods
what is a fat
glycerol combined with 3 fatty acids
what connects fatty acids to glycerol
ESTER LINKAGE
what is a fatty acid
carboxylic acid with an aliphatic chain
saturated fats have
no c-c double bonds
usually solid at room temp
unsaturated fats have
c-c double bond usually liquid at room temp
how to convert unsaturated to saturated fat
hydrogenate- add hydrogen to allow solidification
what produces trans fats
the process of hydrogenating oils
structure of phospholipid
glycerol + 2 fatty acid + phosphate group (+ sometimes choline or serine)
steroid are
carbon skeletons with 4rings
ex of steroid
cholesterol
cholesterol is a precursor to
testoserone and estrogen
how thick is the plasma membrane
8nm thick
the plasma membrane is ‘
FLUID and AMPHIPATHIC
what can some organisms do on demand to their plasma membrane
change the lipid composition (fluidity)
what type of movement can phospholipids drift in
the more often have lateral movement (side by side) or flip flop (opposite side) much less often
what are phospholipids held together by
weak hydrophobic interactions
cholesterol
stabilizes membrane fluidity
HIV cannot infect a cell
that is lacking CCR5
HIV mimics the
structure and conformation of natural ligands for CD4 and CCR5
proteins can move ….
laterally in the membrane
think abt the mouse + human cell combo after 1 hr
in which tube does water flow out of the cell- hyper, hypo or iso
hyper and iso
how does water flow across the membrane of an animal cell
osmosis, facilitated diffusion, aquaporin
malfunctioning of aquaporin is associated with
many diseases of the kidney, skeletal muscle, and other organs
THE MEMBRANE IS
selectively permeable
diffusion of water across a permeable membrane is called
OSMOSIS
what are the 3 types of traffic across the membrane
1) direct passage through
2) passage mediated by transport proteins
- passive or active
3) vericular transport or bulk transport
two types of passive transport : facilitated diffusion
channel protein or carrier protein
electrogenic pump creates
voltage across a membrane
ALL TRANSPORT PROTEINS INVOLVED IN ACTIVE TRANSPORT ARE
CARRIER PROTEINS
in sodium potassium pump describe movement
3 na’s outside cell
2 ka inside the cell
cotransport
gradient generated by one molecule drives the active transport of another
animal cell example of cotransport
glucose uses na+’s gradient to travel against its gradient
exocytosis adds
new components to the plasma membrane
pinocytosis and receptor mediates endocytosis has
coated vesicles
pseudopodium of phagocytosis is powered by
microfilaments
what is a specific example of receptor mediated endocytosis
the uptake of cholesterol
functions of cytoskeleton in eukaryotic cells
structural support and mobility (interaction with motor protein)
which elements of the cytoskeleton are polarized
microtubles and microfilaments
microfilament and microtubles display
a + end and a - end
IF are more
stable and permenent
MF and MT are ___ assembly
rapid … bc are more dynamic
the turgid nature of a plant cell is important for
non- woody plants
exocytosis is base dependent on what?
CALCIUM
microfilaments is made of what filaments
ACTIN
microfiliments structure
two intertwined strands of actin
in microfilaments describe assembly and disassembly
subunits added at the positive end
subunits subtracted at the positive end
ex of microfilaments
microvili increase absorbing area of intestinal cells and their shap is maintained by MF
MF function in regards to muscle
contraction of mucle actin and myosin
the crawling movement of a cell is mediated by
the interaction of myosin motors and microfilaments that alternate polymerization and depolymerization
lamellipodium is
cytoskeletal protein actin projection on the leading edge of the cell- drives cell movement
filopodium functions as an
antennae for cells to probe their environment.
describe the structure of intermediate filaments
supercoiled into thick cables - contains all different types of proteins
what are the functions of intermediate filaments
cell shape, resist tension, cell and nuclear anchorage, and formation of nuclear lamina
a mutation in what causes progeria
lamin mutations
what is progeria
disease that causes accelerated aging in humans
what does lamin mutations lead to alterations in
nuclear disassembly and assembly during cell division, abnormal nuclear architecture, and defective chromosome organization
structure of microtubules
hollow cylindrical rods, made of tubulin dimers
where do cytoplasmic tubules grow out from
centrosomes
which end of a microtubule is the growing tip
positive end is the growing end
function of microtubules
cell shape and organization of cytoplasmic components, track for cellular components (vesicles, chromosome movements require interaction with motor proteins)`
kinesins move towars the _ end of the MT
positive
Dyneins move toward the __ end of the MT
negative
in animals the centrosome has ….
two centrioles
motor proteins require …
energy aka atp
motor proteins are
ATPases (a group of enzymes that catalyze the hydrolysis of a phosphate bond in adenosine triphosphate (ATP) to form adenosine diphosphate (ADP)
what motion do motor proteins have
retrograde motion
cilia and flagella have what specific structure
9 to 2 ring
what describes the movement of cilia and flagella
whipping movement
most abundant thing in the extracellular matrix
collagen
integrins are
a type of plasma membrane protein
fibronectin is a
EMC protein that links with integrins facilitating crosstalk between cell and its environment
Mitochondria and chloroplasts are ….
energy transformers of the cell
enclosed in double membranes
semiautonomous
location not fixed (can move around)
the separating and fusing capabilities of mitochondria and chloroplasts show that they are
DYNAMIC
peroxisomes are single…
membraned
peroxisome functions
breaks down fatty acids and detoxification of alcohol and other poisons
what is a byproduct of peroxisomes
H202 hydrogen peroxide
peroxisome enzymes convert H202 into
Water and oxygen
what is the structure of peroxisomes
crystalloid structure
