ap bio semester 1 exam review Flashcards
emergent property
result from the arrangement and interaction of parts within a system
reductionism
reduction of complex systems to smaller components that are more manageable to study
what organisms are eukaryotic cells
plants, animals, fungi, humans
what organisms are prokaryotic cells
bacteria and archaea
Dna is the ______________ of genes
substance
Chromosomes contain most of a cell’s genetic material in the form of _________
DNA
each chromosome has _____ long DNA molecule
one
Each DNA molecule is made up of ____ long chains arranged in a double helix
two
Each link of a chain is one of four kinds of chemical building blocks called ________
nucleotides
what is a genome
an organism’s entire set of genetic instructions
what is the biological medium on earth
water!!!!!!!!
what type of molecule is water
polar
what does polarity allow water molecules to do
form hydrogen bonds with each other
4 of water’s properties?
-Cohesive behavior
-Ability to moderate temperature
-Expansion upon freezing
-Versatility as a solvent
what is the specific heat of water
1 cal/g/degrees C
why is water’s specific heat traced back to hydrogen bonding
Heat is absorbed when hydrogen bonds break
Heat is released when hydrogen bonds form
heat of vaporization
heat a liquid must absorb for 1 g to be converted to gas
why does ice float in water
because hydrogen bonds in ice are more “ordered,” making ice less dense
what temp does water reach its greatest density at
4 degrees C
what is a hydration shell
each ion is surrounded by a sphere of water molecules
why are certain molecules are hydrophobic
they have relatively nonpolar bonds
what does it mean for water to be in a dynamic state of equillibrium
water molecules dissociate at the same rate at which they are being reformed
Acidic solutions have pH values _____ than 7
less
Basic solutions have pH values ____ than 7
greater
how does carbon form chains
by bonding to itself
what are the functional groups (practice formulas on paper)
hydroxyl
carboxyl
amino
phosphate
carbonyl
methyl
sulfhydryl
macromolecules
large molecules composed of smaller ones
polymer
long molecule consisting of smaller building blocks–> monomers
monomers
make up polymers, specific monomers make up macromolecules
amino acids are the monomers that make up proteins
dehydration synthesis (look at diagrams)
chemical reaction that involves the loss of water from the reacting molecule or ion
allows for monomers to form larger molecules
hydrolysis (look at diagrams)
a compound is broken down into simpler compounds, and is accompanied by the chemical incorporation of water
allows polymers to disassemble
what are the 4 macromolecules
carbohydrates, lipids, proteins, and nucleic acids
what are carbohydrates
serve as fuel and building material
includes sugars and their polymers (mono, di, and polysaccharides)
monosaccharide
simple sugar, may be linear, can form rings
disaccharide
sugar that contains 2 monosaccharides, joined by glycosidic linkage
polysaccharide
sugar that consists of multiple monosaccharides, ex starch, glycogen, cellulose, chitin
Sugars
consist of mono, di, and poly saccharides, used for fuel, converted into organic molecules
starch
storage polysaccharide, polymer of sugar, consists of glucose monomers, major storage form of glucose in plants
glycogen
storage polysaccharide, consists of glucose monomers, major storage form of glucose in animals
cellulose
structural polysaccharide polymer of glucose
major component of tough walls that enclose plants
held together by hydrogen bonds, difficult to digest
cows have microbes in stomach to facilitate process
chitin
structural polysaccharide
found in exoskeleton of arthropods
used as surgical threads
lipids
diverse group of hydrophobic molecules
only class of biological molecules that DONT consist of polymers
share common trait of being hydrophobic
fats
is a lipid
constructed from 2 types of smaller molecules
- single glycerol and 3 fatty acids
2 types
fatty acid
organic acids with long carbon chain
saturated fatty acid
butter
max number of hydrogen atoms
no double bonds
unsaturated fatty acids
multiple hydrogen bonds
double bonds cause bending
phospholipid
2 fatty acids
polar head (hydrophilic)
fatty acid tail (hydrophobic)
bilayer arrangement in cell membrane
steroids
lipids
carbon skeleton
4 fused rings
contains cholesterol
- found in cell membranes
-precursor for hormones
proteins
enzyme
acts as catalyst
speeds up chemical reactions
polymer of amino acids
amino acids
monomer of protein
contains alpha carbon, r-group, and amino and carboxyl function groups
covalently bonded called peptide bonding
polypeptide
polymer (chains) of amino acids with peptide bonds
hydrogen, carbon, nitrogen make up polypeptide backbone
structures of proteins
primary, secondary, tertiary, quaternary
determines function
primary structure
unique sequence of amino acids in polypeptide
AA end and carboxyl end
secondary structure
hydrogen bonded
folding and coiling of polypeptide into repeating configuration
a (alpha) helix
B (beta) pleated sheet
tertiary structure
hydrogen bonded
3 dimensional shape of polypeptide
results from interactions between amino acids and R group
hydrophobic interactions and van der waals
disulfide bridge
hydrogen bonds and ionic bonds
quaternary structure
overall protein structure that results from aggregation of 2+ polypeptide subunits
contains amino acid subunits
protein configuration
depends on physical and chemical conditions of proteins environment
protein configuration
depends on physical and chemical conditions of proteins environment
- temp, pH
denaturation
protein unravels and loses it native conformation
chaperonins
protein molecules that assist in proper folding of other proteins
nucleic acids
store and transfer hereditary info
contains genes
program amino acid sequence of polypeptides
made of nucleotide sequences on DNA
- DNA
-RNA
DNA
stores info for synthesis of specific proteins
found in cell nucleus
directs RNA synthesis (transcription)
directs protein synthesis through RNA (translation)
structure of nucleic acids
exist as polymers–> polynucleotides
polynucleotides
consist of monomers called nucleotides
nucleotides
sugar and phosphate and nitrogenous base
nucleotide monomers
made up of nucleotides
- sugar base and phosphate groups
deoxyribose- sugar in DNA
ribose- sugar in RNA
DNA (nitrogen base)
- C-G and T-A
RNA (nitrogen base)
-C-G and U-A
purines
double ring
(A,G)
pyrimidine
single ring
(C,T,U)
purine must always be with ___
pyrimidine
nucleotide polymer
made up of nucleotides linked by OH on 3’ carbon of one nucleotide and phosphate on 5’ carbon
DNA double helix
cellular DNA molecules
2 polynucleotides spiral around imaginary axis-> forms double helix
consists of 2 antiparallel nucleotide strands
sugar phosphate backbone
base pair joined by hydrogen bonding
base pairing
nitrogenous bases found in DNA
form hydrogen bonds in complementary fashion
adenine (A) and thymine (T)
cytosine (C) and guanine (G)
ester bond
the bond between an alcohol group (-OH) and a carboxylic acid group (-COOH), formed by the elimination of a molecule of water (H2O)
fibrous proteins
made up of polypeptide chains that are elongated and fibrous in nature or have a sheet like structure
globular proteins
spherical proteins, one of the common protein types, somewhat water-soluble
light microscope
visible light passes through a specimen and then through glass lenses, which magnify the image
cant see organelles
eukaryotes
differentiated cells
protists, fungi, animals, plants
prokaryotes
single cell, no nucleus
archae, bacteria
similarites between eukaryotes and prokaryotes
plasma membrane, semifluid substance (cytosol), chromosomes, ribosomes
differences between eukaryotes and prokaryotes
prokaryotes- no nucleus, DNA in unbound region (nucleoid), no membrane bound organelles, cytoplasm bound by plasma membrane
eukaryotes- DNA in nucleus bounded by membranous nuclear envelope, membrane bound organelles, cytoplasm in region between plasma membrane and nucleus, larger than prokaryotes
plasma membrane
- selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service volume of every cell
- general structure is double layer of phospholipids
- 4 ring carbon and cholesterol
limits to cell size
cells have greater surface area relative to volume
metabolism sets limits
what do eukaryotes have that partitions cell into organelles
internal membranes
what are the eukaryotic organelles
nucleus, nuclear lamina, chromatin, chromosomes, nucleolus, ribosomes, endomembrane system, mitochondria, chloroplasts, peroxisomes, mitochondria, chloroplasts, cytoskeleton
nucleus functions
1) houses genetic material
2) most conspicuous organelles
3) nuclear envelope
4) nuclear membrane
5) pores
nuclear envelope
encloses nucleus separating from cytoplasm
nuclear membrane
double membrane, all consists of lipid bilayer
nuclear pores
regulate entry and exit of molecules from nucleus
nuclear lamina
maintains shape of nucleus, composed of protein (lamin)
chromatin
DNA and proteins form genetic materials
chromosomes
condensed chromatin
nucleolus
located within nucleus
contains ribosomes
site of ribosomal RNA synthesis
carries out protein synthesis
found in both eukaryotes and prokaryotes
nucleolus protein synthesis
in cytosol–> free ribosomes
outside of endoplasmic reticulum or nuclear envelope–> bound ribosomes
endomembrane system
regulates protein traffic and performs metabolic functions in cell
contains
- nuclear envelope
- endoplasmic reticulum
- golgi apparatus
- lysosomes
- vacuoles
- plasma membrane
all are either continuous or connected via transfer by vesicles
endoplasmic reticulum
accounts for more than half of total membrane in eukaryotic cells
continuous with membrane
2 regions- smooth and rough ER
plants and animals, not bacteria
smooth ER
lacks ribosomes
synthesizes lipids
metabolizes carbohydrates
detoxifies poison
stores calcium
rough ER
ribosomes studding surface
bound ribosomes secrete glycoproteins
distribute transport vesicles (proteins surrounded by membrane)
membrane factory for cell
glycoprotein
on outside of plasma membrane, compromise protein and carbohydrate chains, membrane carbohydrates covalently bonded to proteins
golgi apparatus
shipping and receiving center
consists of cisternae
modifies products of ER
manufactures certain macromolecules
sorts and packages materials into transport vesicles
cisternae
flattened membranous sacs
entire thing is the golgi
lysosomes
membranous sac of hydrolytic enzymes that digest macromolecules
digestive compartments
endures phagocytosis and autophagy
what do the enzymes do in lysosomes
hydrolyze proteins, fats, polysaccharides, and nucleic acids
phagocytosis
cells can engulf another and forms food vacuoles
fuses with food vacuoles and digests molecule
autophagy
uses enzymes to recycle cells organelles macromolecules
vacuoles
diverse maintenance compartment
- contractile vacuole
- food vacuole
- central vacuole
contractile vacuole
found in freshwater protists
pump excess water out of cells
food vacuole
formed by phagocytosis
central vacuole
found in many mature plant cells
hold organic compounds and water
metabolic activity group
mitochondria, chloroplast, peroxisome, cytoskeleton
mitochondria
sites of cellular respiration that generates ATP
in eukaryotic cells
contains cristae
mitochondrial matrix and intermembrane space
cristae
smooth outer and inner mitochondrial membrane folded together
presents large surface area for enzymes to synthesize proteins
mitochondrial matrix and intermembrane space
inner membrane creates 2 compartments
mitochondrial matrix catalyzes metabolic steps of CR
chloroplast
found in plants and algae (plants and other green organs)
sites of photosynthesis
belongs to plastids (organelle family)
contains chlorophyll (green pigment)
contains enzymes and other molecules functioning in photosynthesis
thylakoids for structure
thylakoids
membranous stacks that form granum and stroma (internal fluid)
peroxisomes
oxidative organelle
specialized metabolic compartments bounded by single membrane
produce hydrogen peroxide and convert to water
oxygen is used to break down different types of molecules
mitochondria and chloroplast structure
change energy to form to another
not part of endomembrane system
double membrane
contain proteins made by free ribosomes
contain own DNA
cytoskeleton
network of fibers extending throughout cytoplasm
organizes cell structure and activity, anchors organelles
- microtubules
- microfilaments
- intermediate filaments
supports cells, maintains shape
interacts with moto proteins (mobility)
may regulate biochemical activities
vesicles travel along ‘monorail’ provided by cytoskeleton
microtubule
thicket component
microfillament
thinnest component
intermediate
fibers w diameters in a middle
microtubules
shape cell
guide movement of organelles
separates chromosomes during cell division
contains centrosomes and centrioles
contains cilia and flagella
centrosomes and centrioles
microtubules grow out from centrosome, near nucleus
centrosome is microtubule- organizing center
animal cells
- centrosome has pair of centrioles
cilia and flagella
microtubules control beating of cilia and flagella (locomotor appendages of cells)
share common ultrastructure
cilia and flagella ultrastructure
core of microtubules sheathed by plasma membrane
basal body anchors cilium or flagella
motor protein (dynein) drives bending movements of cilia or flagellum
microfilaments (actin filaments)
built as twisted double chain of actin subunits
bears tension, resists pulling forces in cell
forms 3D network (cortex) inside plasma membrane
- helps support cell shape
bundles of microfilaments make up core of microvilli intestinal cells
function in cell mobility and contain myosin protein (also actin)
muscles cells have thousands of actin filaments arranged parallel to one another
thicker filaments compose of myosin interdigitate with thinner actin fibers
localized contraction brought about by actin and myosin
-drives amoeboid movement
pseudopodia
cellular extensions
extend and contract through reversible assembly and contraction of actin subunits into microfilaments
cytoplasmic streaming
circular flow of cytoplasm within cell
streaming speeds distribution of materials within cell
plant cell
- actin- myosin interactions and sol-gel transformations drive cytoplasmic streaming
cell walls of plants
extracellular structure that distributes plant cells from animal cells
prokaryotes, fungi, some protists
protects plant cell, maintains shape, prevents excessive water uptake
make of cellulose fibers embedded in polysaccharides and proteins
how many layers do cell walls have
3
plasmodesmata
channels between adjacent plant cells
name major components of cell membrane
glycoproteins, glycolipids, phospholipid bilayer, cholesterol, cytoskeleton filaments, integral membrane proteins, peripheral membrane proteins, carbohydrates, fibers of extracellular matrix
glycolipid
on extracellular surface of cell membrane, membrane carbohydrates covalently bonded to lipids
cholesterol
in between phospholipids, stabilizes cell membrane
cytoskeleton filaments
in the cytoplasmic side of membrane, give cell shape and organize cell parts
integral membrane proteins
within bilayer membranes, penetrates hydrophobic core, helps move molecules across membrane
peripheral membrane proteins
bound to surface of membrane, helps in communication, support, and molecule transfer
carbohydrates (in the membrane)
present on extracellular side of membrane (exterior), attached to proteins and form glycoproteins
extracellular matrix fibers
fills space between cells, in extracellular side of membrane (exterior), helps cell attach and communicate with cells
transmembrane protein
integral proteins that span the membrane
carrier protein
transport protein that binds to molecules and change shape to shuttle them across the membrane, undergo subtle change in shape that translocates the solute-binding site across the membrane
transport protein
allow passage of hydrophilic substances across the membrane, specific for substance it moves, can move solutes against their concentration gradient
integrin protein
mediate interactions between cytoskeleton and extracellular matrix
aquaporins
channel proteins that facilitate the passage of water (facilitated diffusion of water)
channel protein
type of transport protein has hydrophilic channel that certain molecules or ions can useas a tunnel
what does cholesterol do in animal cells
restrains movement at warmer temperatures and maintains fluidity by preventing tight packing at cooler temperatures
6 functions of membrane proteins
transport
enzymatic activity
signal transduction
cell-cell recognition
intercellular joining
attachment to cytoskeleton and extracellular matrix
how can a hydrophobic (nonpolar) molecule pass through the cell membrane
can dissolve in the lipid bilayer and pass through membrane rapidly
how can a hydrophilic (polar) molecule pass through the cell membrane
don’t cross through membrane easily, use facilitated diffusion (carrier and channel proteins) (EX. sugar)
how can ions pass through cell membrane
facilitated diffusion (carrier and channel proteins and ion channels)
how can small molecules pass through cell membrane
enter or leave cell through lipid bilayer or by transport proteins
how can large molecules pass through cell membrane
endocytosis and bulk transport via vesicles
what can monosaccharides pass through cell membrane
diffusion down the concentration gradient
how do carbon dioxide and oxygen cross cell membrane
diffusion, moving from area of high concentration to low concentration
how does K+ move across cell membrane
sodium-pump
how does amino acids and starch cross cell membrane
facilitated diffusion and carrier and channel proteins
active transport
moves substances against their concentration gradient requires energy (ATP) performed by specific proteins embedded in membranes
allows cells to maintain concentration gradients that differ from their surroundings
sodium-potassium pump
type of active transport system
major electrogenic pump of animal cells
PROCESS
1) cytoplasmic Na+ binds to sodium potassium pump
2) Na+ binding stimulates phosphorylation by ATP
3) phosphorylation causes protein to change its shape expelling Na+ to the outside
4) K+ binds on extracellular side and triggers release of phosphate group
5) loss of phosphate group restores protein’s original shape
6) K+ is released and cycle starts over
passive transport
diffusion of a substance across a biological membrane with no energy required from the cell to make it happen
diffusion
net movement of molecules from a higher area of concentration to an area of lower concentration (even spreading of molecules)
facilitated diffusion
transport proteins speed the passive movement of molecules across plasma membrane
osmosis
diffusion of water across selectively permeable membrane
pinocytosis
active transport, type of endocytosis, molecules are taken up when extracellular fluid is “gulped” into tiny vesicles (cellular drinking)
phagocytosis
active transport, type of endocytosis, cell engulfs a particle in a vacuole (cellular eating), vacuole fuses with lysosome to digest particle
3 types of endocytosis
pinocytosis, phagocytosis, receptor-mediated endocytosis
endocytosis
active transport
cell takes in macromolecules by forming vesicles from plasma membrane, reversal of exocytosis
exocytosis
active transport
transport vesicles migrate to the membrane, fuse with it, and release their contents, used by secretory cells to export their products
isotonic
solute concentration is the same as that inside the cell; no net water movement across cell membrane
hypotonic solution
solute concentration is less than that inside the cell; cell gains water
hypertonic solution
solute concentration is greater than that inside the cell; cell loses water
osmoregulation
the control of water balance, is a necessary adaptation for life in such environments
amphipathic
molecule that contains both hydrophobic (nonpolar) and hydrophilic (polar) parts
receptor- mediated endocytosis
binding of ligands to receptors triggers vesicle formation
ligand
any molecule that binds specifically to a receptor site of another molecule
how does bulk transport occur
endocytosis and exocytosis
cotransport
occurs when active transport of a solute indirectly drives transport of another solute
electrogenic pump
a transport protein that generates voltage across a membrane
proton pump
main electrogenic pump of plants, bacteria, and fungi
electrochemical gradient
two combined forces drive diffusion of ions across membranes
chemical and electrical force
chemical force
the ion’s concentration gradient
electrical force
the effect of the membrane potential on the ion’s movement
membrane potential
voltage difference across a membrane
why is facilitated diffusion passive
the solute moves down the concentration gradient
ion channel
channel protein that open or close in response to a stimulus (gated channel)
plasmolysis
in hypertonic environment plant cells lose water, membrane pulls away from wall, death to plant
what do cell walls help to maintain
water balance
turgid
plant cell in hypotonic solution (ideal) swells until the wall opposes uptake, causes cell to become firm
flaccid
plant cell and surroundings in isotonic solution with no net movement of water into cell, plant becomes limp and may wilt
what problems do hypertonic and hypotonic solutions create
osmotic
tonicity
the ability of a solution to cause a cell to lose or gain water
