-
6 major funcitons of proteins
structure transport, catalysis, regulation and signalling, motors, protection
-
polypeptide chain
a linear unfoled chain of 30+ amino acids
-
peptide
a short chain of 2-30 amino acids
-
how many different amino oacids are there
over 20
-
what does an amino acid consist of
- a central carbon surronded by a hydrogen
- amindo (NH2) group
- carboxyl (COOH) group
- a unique r group
-
different r groups have different....
biochemical properties
-
three main classes of amino acids
- hydrophillic
- hydophobic,
- unique
-
describe a polar hydrophillic R group/amino acid
- found on the surface of a protein
- some are charged others are not
- charged ones act as an acid or base
- uncharged ones hydrogen bond wiht water
-
describe nonpolar hydophobic amino acids/R groups
- usually buried in a protein to get a way form the water
- have hydrocarbon rings or chains
-
describe unique r groups/ amino acids
have a unique biochemical protein that can alter the function of the entire protein
-
how do peptides and polypeptides form
- the amino group of on amino acid reacts with the carboxyl group of an agjacent amino acid
- water is removed and the peptide bond is formed
-
where does the formation of polypeptides and peptides take place
in the ribosomes
-
all polypeptides have two ends what are they
n terminus and c terminus
-
n terminus
free NH2 group
-
c terminus
free COOH group
-
the function of a protein is extremely depentant on its ...
specific shape
-
primary structure of a polypeptide
- a linear string of amino acids
- order determined by dna
- linking of amino acids is not random
-
secondary structure of polypeptide
- hydrogen bonds between two different amino acids in the polypeptide chain bettween amino and carboxyl
- hydrogen bonds cause two different structures called secondary structures
-
what are the two types of secondary structures
alpha helix and beta sheet
-
tertiary structure of a polypeptide
interactions between amino acid side chain r groups leads to further twisting allowing secondary structures to interact
-
what are the 5 tyoes of interactions between r groups in the tertiary structure of polypeptides
- hydrogen bonding
- hydrophobic interactions
- van der waals interactions
- ionic bonds
- disulfide bridges----covalent bonds
-
quaternary structure of polypeptide
2 or more polypeptide chains bonded together
-
it is very difficult ot disrupt a polypeptides....
primary structure
-
the disruption of hte bonds in the 2-4 structures of polypeptides leads to....
unwinding/ changing of hte polypeptide shape, disrupting the proteins 3D structure -----denaturing
-
denaturing usually results in a loss of
protein function
-
what are nucleic acids
long polymers made up of small monomers called nucleotides
-
what are the two major types of nucleic acids
- Deoxyribonucleic acid
- Ribonucleic acid
-
describe DNA
- stores heretidary information
- double stranded
- contains four types of nucleotides
- strands interact via hydrogen bonds
- contain deoxyrobse sugar
-
describe RNA
- transfers the herediary information
- single stranded
- 4 types of nucleotids
- contains the sugar ribose
-
what are nucleotides
- a sugar, five carbon ring (ribose or deoxyribose)
- one or more phosphate groups
- a nitrogen containing base-- single or double carbon ring structure ---makes them different from eachother
-
what tyoes of bases does DNA have
A T C G
-
what types of bases does RNA have
A C U G
-
all cells have a similar -----
basic structure,chemical composition, and a set of metabolic pathways
-
what is magniication
increasing apparent size
-
what is resolution
distinguishing two parts
-
what does resolution depend on
wavelength of light
-
what are the two kinds of microscopes used today
light microscopy and electron microscopy
-
light microscopy can intensify the objecy_____times
1000
-
what are the three kinds of light microscopes
- visible light,
- uv light
- light laser
-
describe visible light microscope
enhances contrast in unstained cells
-
describe a uv light microscope
flourescence, for tagging proteins
-
describe light laser microscope
confocal ised to observe thin section of a thick sample
-
what are the two types of electron micropscopes
- scanning EM
- transmission EM
-
describe scanning em
- gives great 3D images
- surface topography
- electrons shoots the surface of the sample
-
describe a transmission em microscope
- gives fine detail on internal cellular components
- electrons shoot through a thin sample
-
samples must me ____ in electronmicroscopy
fixed, dead
-
electron micropscopes can see ___ than light microscopes (1000x)
100x
-
the greater the suface area of the plasma membrane the _____ that are brought in and the cell is healthier
nutrients is brought in
-
as the cells diameter expands so does the ...
suface area and volume
-
based on math equations , as the the volume of a cell ____ ____ than the surface area of the plasma membrane
increases faster
-
if a cell grows too large what happens
the plasma membrane will be unable to bring in nutrients fast enough to support hte increased amount of hte cytoplasma the cell will die
-
what does the plasma membrane do for the cell
- protects the interior form the outside
- allows biochemical reactions to proceed in a controlled environment
-
where ar chromosomes found in both eukaryotic and prokaryotic cells
in teh nucleus (e) or in the cytoplasm around the nuceolus (p)
-
what do ribosomes do
they are machines that construct polypeptides from amino acids
-
-
what two types of organisms are made up of prokaryotic cells
eubacteria (monera) and archeabacteria
-
what type of cell is thought ot evolved first
prokaryotic
-
what are four thiings the plasma membrane does
- controls movement
- separates chemical reactions form harsh environment
- helps relay messages into the cell
- regulates chemical compostion of the cytoplasm
- ---controls the volume of the inside of hte cell
-
what does the plasma membrane consist of
phospholipids, cholesterol, embedded proteins (liipid bilayer)
-
what does the nucleus do
- protects and organizes genetic material
- organizes production of ribosomes
- the site where the genetic code is read and captured to RNA
-
what does the nucleus look like
-
what are the four key features of the nucleous
- nuclear envelope
- nuclear lamina
- chromosomes
- nucleolus
-
describe the nuclear envelope
- double layer membrane
- has nuclear pores
- selects substances to go in and out of nucleus
-
describe the nuclear lamina
- meshwork of protein filaments that line th inner layer of hte envelope
- gives nucleus its structural support and shape
-
describe chromosomes
- DNA inside the nucleus is coiled around proteins that protect the DNA from toxins
- the split pieces of DNA and its associated proteins are called chromosomes
-
describe the nucleolus
- dense mass in nucleus
- where ribosomal subunits are assembled
-
how are ribosomal subunits made?
mad eof protein and rRNA that is shipped into the nucleolus
-
what do ribosomes do
they read the genetic message in mRNA and assemble amino acids in to specific proteins
-
what do ribosomes look like
- solid granules of protein adn rRNA
- composed of one large nad one small subunit
-
where are ribosomes found
attacted to internal cellular membranes or free in the cytosol
-
what are membrane bound ribosomes
- the make proteins that are destined to be inserted into membranes
- shipped to the inside of organelles or shipped out of the cell
-
what are free ribosomes
generally make proteins that stay in cytosol
-
what does endoplasmic reticulum (ER) look like
network of sacs that are connect ot eachother some are studded with ribonsomes
-
what are the individual sacs of ER called
cisternae
-
what is the empty space in cisternae called
ER lumen
-
smooth ER looks like...
tubes
-
what are the four things smooth ER does
- synthesis of proteins
- metabolism of carbohydrates
- detox of drugs and poisens
- store calcium ions in certain cell types
-
what are the two things rought ER does
- protein synthesizer
- membrane synthesis
-
little tiny sacs of membrane are called...
vesicles
-
what does the golgi apparatus look like
- flattened interconnected cisternae (pancaked)
- one side close to ER the other away from
-
what is the cis face
the side of the golgi apparatus that is close to the ER
-
what is the transface
the side of the golgi apparatus that is facing away form teh ER
-
what are the three things the golgi apparatus does
- makes several types of carbohydrates
- receives proteins form the rough ER (via vesicles from the ER ------to the cis face) and puts finishing touches on them
- packages proteins and directs where they need to go in the cell
-
what are glycoproteins
ER made proteins that have sugar groups attached to them
-
what do lysosomes have in them
- acid
- hydrolic (digestive) enzymes
- other toxic substances
-
what do lysosomes look like
typical vesicles
-
where are lysosomes derived from
the trans golgi
-
what are the two things lysosomes do
- destroy large items brought in from the outside of the cell
- destroy ol organells and recycle them
-
what do peroxisomes look like
similar to lysosomes
-
what is the function of peroxisomes
- the convert substances to H2O2
- they help tetoxify the cell by removing hydroogen form the toxins and transfers that to O leaving H2O2 which is further broke down to water
breakdown of fatty acids and transports them to the mitochondria
-
what do the mitochondria do
- they are major ATP producers fo the cell.
- they breakdown organic compunds in to CO2 / H2O extract the energy and make ATP
-
what do mitochondria look like
- a bean
- double membrane
- inner membrane is folded
-
what is the inner folds of the mitochondria called
cristae
-
what is the inner space of the mitochondria called
matrix
-
the mitochondria is inherited form the
mother
-
most plant cells contain a category of organelles call ____ that specialize in photosynthesis and food storage
plastids
-
what are the three main types of plastids
- chloroplasts
- chromoplasts
- amyoplasts
-
what is chloroplast
the structures responsible for photosynthesis
-
what is chromoplast
they lack chloroplast but have other photosynthetic pigments
-
what is amyoplast
lack all pigment --no photosynthesis-- help store starch
-
what is the structure of chloroplast
- double outer membrane (smooth)
- third internal membrane forms sacs
- a fluid filled space outside of the sacs
- process their own DNA and ribosomes
-
what are the individual sacs of chloroplast called
thylakoid
-
what is the fluid filled space outside of the thylakoid called
stroma
-
a stack of thylakoid is called...
granum
-
describe a vacuole
- gigantic vesicle found in plants
- has similar degradative enzymes as lysosomes
- they degrad polymers,proteins,carbs and fats into monomers
- regulates cell size
-
what is the universal storage facility for plant cells
vacuoles
-
what do vacuoles store
amino acids, sugars, ions toxic substances ect
-
what is the cytoskeleton
a dense network of interconnecting protein filiments and cylinders
-
what are the three functions of hte cytoskeleton
- give the cell overall shape and structural support
- helps organize cellular components
- cellular movements
-
what are microtubules
large hollow rods composed of the protein tublin
-
what protein makes up microtublues
tubulin
-
what are the functions of the microtubules
- shape and support of the cell (push and pull)
- provide organized framework for travel
- moving parts or whole cell
-
what are cilia and flagella
extensions from the plasma membrane that move and as a result creat movement of hte cell
-
what is the 9 to 2 arrangemetn
microtubules made up of 9 doublets arranged in a cylindar wiht another in the middle
-
microtublues are associated with the motor protein....
dyein
-
cilia---
small hair like structures
-
flagella
longer whip like structures
-
what type of movement does flagella create
whip like motion moves whole cells
-
what type of movement does cilia create
beating motion that can move hte whole cell or substances around the cell
-
who do cilia move
like oars
-
how do flagella move
like propellers
-
what are microfiliments
- large solid rod composed of actin
- huge networks
-
what are the two functions of microfiliments
- shape and support
- ---under the plasma membrane , supports against pulling --supports microvilli
- cell movement via pseudopodia or microvilli
-
what is the intermediate filament
- made of different proteins mostly keratin
- makes up nuclear lamina
-
what does the intermediate filaments do
- mostly structural support
- help cell maintain shape
- anchor the nucleus and other organelles in place
-
what are the nonmembrane enclosed structures found outside the plasma membrane
cell wall, extracellular matrix, and intracellular junctions
-
plant cell walls contain lots of _____ embedded in their polysaccharides and various proteins
cellulose
-
describe the cell wall
surrounds the plasma membrane and rovides strength , support and protection
-
the cell wall is made by ...
themselves and sent out
-
animal cells have a ____ instead of a cell wall
extracellular matrix
-
what is an extracellular matrix
thick loosley arranged network of various glycoproteins outside of plasma membrane
-
what are four components of the extracellular matrxi
- -collegen (most abundant)
- -proteoglycans
- -fibronectin
- -integrins
-
what is a proteoglycan
long sticky glycoprotein that keep the other parts ofhte ECM stuck together
-
what does fibronectin do
attach some ECM proteins tot he plasma membrane
-
what do integrins do
embedded in the membrane they can signal to the inside if something is happending outside the cell
-
what are intercellular junctions
connections between cells that help them stick together and communicate with one another
-
what are the 3 major types of intracellular junctions in animals
- tight junctions
- desmosomes
- gap junctions
-
tight junctions
- super glue
- encircles entire cell
- water tight seal
- composed of adhesion protein filaments
-
desmosomes
- elasic bands between cells
- allow for stretching
- consists of glycoprotein filaments that do not completely surround the cell
-
gap junctions
- protein complexes that form a channel (pore) between 2 neighboring cells
- allows communication and exchange of nutrients
- do not encircle
-
what is the only type of intracellular junction in plants
plasmodesmata
-
plasmodesmata
- channels between 2 adjacent [plant cells
- connects cytoplasm
- allows water, ions and nutrients to flow form cell to cell (like gap)
- helps cell wall keep plant cells glued ot eachother
- share a cell wall with neighbor
-
what really holds cell walls together
polysaccharides
-
what are the two groups that cellular chemical reactions can be placed in
- -those that involve the breaking down of large molecules into simpler ones
- -those that are involved in building up of larger more complex molecules
-
breakdown reactions are called ---- and ----
catabolic reactions ---- release lots of energy
-
build up reactions are called ____ and ______
anabolic reactions---- require energy
-
what are the three types of cellular work?
- anabolism macromolecules synthesized
- mechanical work
- electromechanical work
-
what is anabolism macromolecules synthesized
- making of proteins from amino acids
- making of DNA from nucleotides
-
what is mechanical cell work
-
what is electromechanical cellular work
active transport (shipping things in and out of the cell)
-
what is a catabolic pathway
the long series of controlled steps that a cell goes through to extract energy
-
why do cells follow the catabolic pathway
- to prevent damage from extractng too much energy at once
- and to maximize efficiency
-
a cell must constantly _____ their anabolic and catabolic reactions
balance and regulate
-
define metabolism
the sum of hte anabolic and catabolic reactions in a cell
-
how is energy pransfered from one process to another
ATP
-
what is ATP
- Adenosine triphosphate
- contains the sugar ribose
- a nitrogenous base adenine
- three phosphate groups
- very stable
-
how is ATP made
the energy produced from catabolic reactoins is used to take a phosphate group and add onto a molecule of ADP
-
what does ADP stand for
adenosine diphosphate
-
how do you use the energy in ATP
the last phosphate is taken off breaking the bond (by hydrolysis)--releasing all the energy you put in
-
define a chemical reaction
the process that leads to the changing / making and or breaking of chemical bonds ----requires energy
-
what is activation energy
the energy required to get a reaction going
-
where do reactants acquire thier activation energy
heat from surrounding environment
-
most chemical reactions have a very_____ activation energy requirement
high
-
what is a catalyst
a substance that can speedup a reaction with out being used up
-
catalysts in cells are called
enzymes
-
how do enzymes speed up the chemical reaction
they lower teh activationenergy barrier and allow reactions to happen with much less energy
-
what are the three ways enzymes lower the activation energy
- -the bind to reactants (substrates) and twist them so that the existing bonds are destabalized
- -the find substrates and orient them properly so that they are more likely to interact
- -provide a microenviroment that is conductive to the reaction
-
what are 5 properties of enzymes
- -very specific (lock and key) an enzyme usually only catalizes one reaction
- -binding to substrates is temporary -recycled
- -the speed up reactions without the need for an increase in temp,press, ect
- -extremely fast and efficient
- -exist in active and inactive forms
-
what 5 factors affect enzyme activity
- temp
- pH
- salt concentration
- coenzymes
- inhibitors
-
enzyme activity ____ as temp____
increases---increases
-
too high of a temp can cause enzymes to
denature
-
most enzymes work best at a pHs of
6-8
-
pepsin works best at a pH of
2
-
most enzymes dont work very well in ____ water
pure
-
why do enzymes not work well in pure water
they need ions to allow for proper ionic and hydrogen bondong between enzymes and substrates
-
if the salt concentration is too high it can interfere with enzyme activity by---
interfering with enzyme substrate interactions
-
some inhibitors are _____
reversible
-
how do competitive inhibitors work
they resemble the substrate and block the acitve site
-
what is another name for noncompetative inhibitors
allosteric
-
how do noncompetative inhibitors work
binds to enzyme in a p;lace other than the active site and indirectly causes the active site to change no longer recognizing the substrates
-
what is feedback inhibition
the final product of the enzymatic reaction goes back and allosterically inhibits the first enzyme in the series
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