biochem, test two Flashcards
the eleven cell organelles are:
nucleus, DNA/chromosomes, ribosomes, endoplasmic reticulum, lysosomes, mitochondria, golgi apparatus, cytoplasm, vesicles, vacuole, cell membrane
function of the nucleus:
contains and protects genetic material (DNA)
function of DNA/chromosomes:
information for making proteins
function of ribosomes:
make proteins
function of endoplasmic reticulum:
transports and finishes proteins and other biological molecules
function of lysosomes:
catalyze hydrolysis reactions, breaks down macromolecules
function of mitochondria:
synthesizes ATP
ATP is:
a nucleotide with three phosphate groups; breakdown of ATP creates energy
function of golgi apparatus:
packages, processes, sorts, and distributes proteins, lipids, and other substances within the cell
function of cytoplasm:
medium for chemical reaction, provides a platform upon which other organelles can operate within the cell
region of the cell contained within the cell membrane
function of vesicles:
cellular package containing products like protein
function of cell membranes:
controls the flow of substance into and out of the cell
how is a cell like a factory? nucleus
control room
how is a cell like a factory? DNA/chromosomes
factory manager
how is a cell like a factory? ribosomes
assembly workers
how is a cell like a factory? endoplasmic reticulum
production line
how is a cell like a factory? lysosomes
custodians
how is a cell like a factory? golgi apparatus
shipping department
how is a cell like a factory? cytoplasm
factory interior
how is a cell like a factory? vesicles
items to be shipped
how is a cell like a factory? vacuole
warehouse for storage of products
how is a cell like a factory? cell membrane
security fence
cell theory states that:
- all living things are made of cells
- new cells are created by pre-existing cells
- cells are the building blocks of life
the two types of cells are:
eukaryotic and prokaryotic
eukaryotic cells have x and x whereas prokaryotic cells do not.
nucleus and membrane-bound organelles
common features of eukaryotic cells:
- DNA is contained within a membrane-bound nucleus
- cell membrane made up of phospholipid bilayer and proteins separating the intracellular/extracellular environments
- cytoplasm filling the space between cell membranes and nucleus, consisting of cytosol
the cell theory states that:
- all living things are made up by cells
- new cells are created by pre-existing cells
- cells are the building blocks of life
all eukaryotic cells contain three common features:
- DNA contained within a membrane bound nucleus
- a cell membrane consisting of a phospholipid bilayer and proteins that separates the intracellular and extracellular environments
- the cytoplasm, which fills the space between the cell membrane and nucleus (consists of cytosol and cell organelles)
the four distinct parts of the nucleus are:
the nucleoplasm, the nucleolus, the nuclear envelope, and the nuclear pores
the nucleoplasm is:
the fluid portion of nucleus that contains DNA and the nucleolus
the nucleolus is:
the denser region containing RNA, protein, and chromatin
the nuclear envelope is:
a double membrane made out of a phospholipid bilayer between the nucleoplasm and the cytoplasm.
the lumen is:
the space between the lipid bilayer
the nuclear pores are:
the openings formed by proteins between nucleus and cytoplasm that allow small essential particles like water and ions through while preventing the passage of larger macromolecules in the cytoplasm.
the location of the endomembrane system is:
in the membranes within the cell.
the endomembrane system consists of:
the ER, the golgi apparatus, vesicles, the cell membrane, the nuclear envelope, lysosomes, and vacuoles.
the function of the endomembrane system is:
to synthesize, modify, and transport proteins and other cell products.
the endoplasmic membrane consists of:
tubes and sacs composed of folded membranes throughout the cell.
the rough ER:
- studded with ribosomes where proteins are produced
- connected to the nuclear envelope
the smooth ER:
has no ribosomes attached to it
- involved in lipid and steroid production and detoxification
the golgi apparatus is made out of:
membranous sacs
the membranous sacs that make up the golgi apparatus are called:
cisternae. they resemble flattened pancakes.
the function of the golgi apparatus is to:
modify the products of the ER and sort and package the materials into transport vesicles.
in plant cells, the golgi apparatus sunthesizes:
pectin
pectin is:
a structural polysaccharide used in cell walls
in animal cells, the golgi apparatus produces:
lysosomes.
lysosomes break down:
macromolecules
lysosomes break down macromolecules by:
catalyzing hydrolysis reactions.
glycoproteins happen when:
carbohydrate chains are added to proteins
lipoproteins happen when:
lipids are added to proteins
lipoproteins transport:
fats through blood
glycoproteins are important parts of:
the cell membrane
in proteins, R groups:
dictate polarity
peroxisomes are:
membrane bound vesicles that contain the enzyme oxidase.
oxidase helps enzymes:
catalyze redox reactions
peroxisomes are used to:
- break down fats
- produce bile salts
- oxidize + break down alcohol molecules
catalase is:
an enzyme that breaks down hydrogen peroxide into water and oxygen gas.
vacuoles are:
larger versions of vesicles. they store water, ions, macromolecules, sugars, amino acids, and toxic substances.
in plants, the central vacuole is:
a large fluid filled sac.
turgor pressure is:
the force that provides structural support to the cell by making the cell rigid
chloroplasts are:
only found in plant cells
chloroplasts are:
involved in photosynthesis
chlorophyll is:
a photosynthetic pigment inside the chloroplast that absorbs light energy and converts carbon dioxide and water into water and energy-rich carbohydrates.
mitochondria carry out:
cellular respiration (produces energy)
mitochondria posses:
a double membrane and their own DNA
the four main types of chemical reactions that occur in biological processes are:
- neutralization
- redox reactions
- condensation
- hydrolysis
amphiprotic means:
a molecule can be used as a base and acid.
the autoionization of water forms:
very small concentrations of the hydroxide ion and the hydronium ion
acids:
- have a sour taste
- conducts electricity
- turns blue litmus paper red
- increases the conc. of H3O+
- is an h+ (proton) donor (produces h+ in water)
bases:
- have a bitter taste
- are slippery
- conduct electricity
- turn red litmus paper blue
- is an H+ acceptor (produces OH- in water)
substances are ranked on the pH scale according to:
their relative h+ concentration
water is nuteral on a pH scale because:
it has an equal concentration of h+ and oh-
neutralization reactions occur when:
when an acid reacts with a base
neutralization reactions result in:
the formation of a salt and water
human blood has a pH range of:
7.35 - 7.45
alkalosis occurs when:
blood pH rises above 7.45
acidosis occurs when:
blood pH falls below 7.35
blood pH can increase if someone:
breathes too quickly at high altitudes, feels extremely anxious , or takes too many antacids.
if too much CO1 builds up in the blood, blood pH can fall to within:
7.1 - 7.3
organisms rely on buffers to:
maintain optimum pH ranges.
buffers work by:
removing H+ when a fluid is too acidic and donating H+ when a fluid is too basic.
most buffers exist as:
acid/base pairs
the most important buffer system in human blood is the :
carbonic acid/bicarbonate ion pair.
redox reactions involve:
the transfer of one or more electrons from one atom to another.
oxidization occurs when:
an ion loses one or more electrons
reduction occurs when:
an atom gains one or more electrons.
a reducing agent is:
a substance that loses an electron in a redox reaction (causes reduced atom to become reduced)
an oxidizing agent is:
a substance that gains an electron in a redox reaction (causes the oxidized atom to become oxidized).
anabolic reactions result in:
the construction of larger molecules from smaller subunits.
catabolic reactions:
break macromolecules down into subunits.
hydrolysis is the process of:
adding water to break covalent bonds between subunits
activation energy is:
the amount of time required from a reaction for it to be initiated
a catalyst is:
a substance that speeds up the rate of a chemical reaction by lowering the activation energy for the reaction.
enzymes are protein catalysts that:
speed up a chemical reaction without being consumed in the process.
we need enzymes to speed up important biochemical reactions that have a high activation energy because:
it would take too long for them to happen organically
EA (activation energy) is a:
barrier that must be overcome in order for the reaction to proceed
all enzyme names end with:
ase!
the substrate is:
the reactant that the enzyme acts on when it catalyzes a chemical reaction.
the active site is:
a particular pocket or indentation on the globular surface of the enzyme that the substrate binds to
the enzyme-substrate complex is formed when:
an enzyme and substrate bind with each other
induced fit happens when:
the shape of the enzyme changes slightly to better accommodate the substrate, forming intermolecular bonds, such as hydrogen bonds.
enzymes can lower the activation energy of a reaction. the active site may:
- make the bonds in the substrate easier to break by bending/stretching them with similar R-groups.
- change the pH of the substrate, use redox reactions, or bring substrates together in the correct position to facilitate the reaction
optimal body temperature for humans:
37 degrees c.
the catalytic cycle is:
the cycle of enzyme-substrate bonding, releasing, and repeating.
cofactors are:
non-protein components that enable enzymes to function
two examples of cofactors are:
iron and zinc
coenzymes are:
organic non-protein cofactors that are needed for enzyme function
competitive inhibitors:
block the active site (they have the same shape as the substrate)
non-competitive inhibitors:
attach to a different site on the enzyme that changes the shape of the active site
where do non-competitive inhibitors bind?
the allosteric site of an enzyme
define allosteric regulation
the regulation of enzyme activity in the body using activators and inhibitors
allosteric activation:
when a regulatory molecule binds to the allosteric site, allowing the substrate to bind to the active site
allosteric deactivation:
when a regulatory molecule binds to the allosteric site and changes the formation of the active site so that the substrate cannot bind
centrioles are used during:
cell division to move and separate chromosomes (only found in animal cells)
the cell wall is made out of:
cellulose
there is a cell wall surrounding the cells of:
plants, fungi, protists and bacteria
what can pass through the cell wall freely?
water, gases, and small substances
the cytoskeleton consists of:
microtubules, microfilaments and intermediate filaments (types of protein fibers)
the cytoskeleton extends:
throughout the cytoplasm, from the nucleus to the cell membrane
microtubules are:
hollow protein tubes composed of a protein called tubulin
microtubules help:
maintain the cell’s shape, act as tracks that facilitate organelle movement, and assist spindle fiber formation during mitosis (cell division)
microfilaments are:
two chains of actin twisted togehter
the function of microfilaments is as follows:
- maintain cell shape
- involved in muscle contraction
intermediate filaments are composed of:
fibers composed of a variety of proteins (tough and rope-like)
the function of intermediate filaments is as follows:
- maintain cell shape
- support the cellular and nuclear membrane
- anchor organelles
- form internal scaffolding of the nucleus
cilia and flagella are involved in:
cell movement
cilia:
shorter hair-like structures that beat stiffly like oars. can be found lining the respiratory tract, helping to sweep debris away from the lungs.
flagella:
longer tail-like structures that are analogous to oars in a row-boat, steering the cell’s direction. sperm
the cell membrane provides:
a necessary barrier between the inside and outside of the cell
the cell membrane is:
a very thin, selective barrier that controls the molecules and ions that enter/exit the cell.
integral proteins are located:
in the cell membrane (embeded)
peripheral proteins are located:
on the outer surface of the lipid bilayer
define semi-permeable:
allows some substances to pass through and acts as a barrier for other substances
passive transport:
when substances pass across the membrane without the input of energy
a concentration gradient exists when:
there is a difference in concentration of a substance outside of the cell versus inside of the cell.
the three forms of passive transport are:
diffusion, osmosis (water only), faciliated diffusion
diffusion happens when:
substances move from regions of higher concentrations to lower concentrations.
diffusion will continue until:
the concentration of the substance is the same in all regions.
factors that affect the rate of diffusion are:
- molecule size
- molecule polarity
- molecule or ion charge
define osmosis:
movement of water molecules through a selectively permeable membrane from higher water concentration to lower water concentration
facilitated diffusion:
diffusion with help from a membrane protein.
in diffusion, higher temperatures cause molecules to:
move faster as molecules have more energy
osmotic concentration is determined by:
the concentration of solute in the soloution
tonicity is:
the relative concentration of solutes on both sides of the membrane
hypertonic:
more than
hypotonic:
less than
isotonic:
equal to
channel proteins have a hydrox interior:
hydrophobic (allows polar molecules to pass)
an aquaporun is:
a channel protein for water
active transport:
transport against the concentration gradient, requires energy
primary active transport:
uses ATP to move molecules across cell membrane, against conc gradient
sodium potassium pump:
is an example of primary transport. it moves sodium ions out of the cell while moving potassium ions into the cell. more sodium ions leave the cell than potassium ions enter, difference of charges
sodium potassium pump, numbers:
three sodium ions leave the cell, two potassium ions enter
secondary active transport uses:
an electrochemical gradient as a source of energy to transport molecules across a cell membrane
membrane assisted transport use:
vesicles to transport larger molecules across the membrane
the two types of membrane assisted transport are:
endocytosis and exocytosis
endocytosis is:
membrane assisted transport entering the cell
exocytosis is:
membrane assisted transport exiting the cell
the three types of endocytosis are:
phagocytosis, pinocytosis, and receptor mediated endocytosis
phagocytosis:
when the membrane extends around an organism and engulfs it, forming a vesicle.
pinocytosis:
when cells take up liquid particles
receptor mediated endocytosis:
when a shallow depression in the cell membrane containing receptor proteins, called a coated pit, binds with specific molecules and folds inward to form a coated vesicle.
channel vs carrier proteins:
- channel only transport down transportation gradient, carrier does both
- conformation of channel is the same at all times while carrier proteins switches between two
- channel are all lipoproteins
- carrier are all glycoproteins
step 3 of enzyme substrate complex:
alpha 1-4 glyosidic bonds are broken by hydrolysis
