Quiz 1 (From Lect. 1) Flashcards
how do cells know what to do or how to behave?
cell signaling
what is cell signaling
process by which cells communicate with each other to coordinate various functions necessary for the body’s development, homeostasis, and response to external stimuli. This communication is essential for maintaining the organization and function of multicellular organisms
what is biochemistry
study of molecular basis of life
what are atoms
have an unequal number of protons and electrons resulting in no net charge
smallest units of ordinary matter that retains the chemical properties of that element
when are atoms the most stable
when outermost electron shell is full
what happens when the outermost electron shell is not full
chemically unstable
what is an uncharged atom
radical
what are ions
atoms or molecules that have gained or lost one or more electrons resulting in a net positive or negative charge
first inner ion ring holds
2 es
second inner ring holds
8 e
third ring holds
18 e
fourth ring holds
32 e
what makes an ion a positive charge
when atomic shell loses electrons there are more protons than electrons
one for each unbalanced proton
what is a cation and an examplr
positive charged ion (Na+
what makes an ion a negatve charge
when electrons are added to the shell there are more electrons than protons
one for each extra electron
what is an anion and an example
negative charged ion (Cl-
what are common ions in the body and cochlea
Na+, K+, Cl-
describe electrolytes
facilitate conductance of electrical current
electrostatic attraction between +ve & -ve ions brings the particles together and creates an ionic compound, such as sodium chloride – NACL (salt)
derived from an atom by either losing or gaining electrons resulting in a charged entity
ion
what is a molecule
groups of atoms (2 or more) chemically bonded together representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction
smallest unit of a pure substance that has all of the properties of that substance
what is equal to the atomic number (Z)
of protons in the nucleus of the atom
what is an ex of molecules
water
2 hydrogen & 1 oxygen & together they make water (molecule)
single units of elements with no charge (neutral)
atoms
charged atoms or molecules due to the loss or gain of electrons.
ions
are combinations of two or more atoms bonded together, which can be either neutral or charged (if they form ionic compounds)
molecules
atoms are the building blocks of matter, ions are charged versions of these building blocks, and molecules are combinations of atoms bonded together
true
basic unit of matter
atom
gain/loss of electrons
ions
chemical bonds bw atoms
molecules
ex of atoms
H
O
ex of ions
sodium ion (Na+
Chloride ion (Cl-)
ex of molecules
Water (H₂O), Carbon dioxide (CO₂), Ammonium ion (NH₄⁺)
what are free radicals
atoms, molecules, or ions that contain an unpaired electron in their outermost shell, making them highly reactive and unstable.
why can free radicals easily engage in chemical reactions with other moleules? what is the result?
because of the unpaired e
resulting in the formation of new free radicals and leading to a chain reaction.
in humans, free O2 radicals are released from many processes of cell chemistry
too many damage other molecules over time, producing some aging effects and some cancers
true
what is a compound and an ex
reproducible no matter how many times you do it & you can break it down
combination of </= 2 elements with a chemical union and combine in a reproducible way
able to be converted into simpler forms by chemical means
ex: H2O can be converted to hydrogen and oxygen through heat
all compounds ae molecules but not all molecules are compounds
true
compounds are always consistent of atoms of different elements
molecules can consist of atoms of the same or different elements
what is a mixture
consists of two or more different elements and/or compounds physically intermingled
able to be separated into its components by physical means
retains many of the properties of its components
just like a mixed drink, you can separate all of the components
sugar & water, tea & sugar are good examples
what is a non-uniform mixture
Consists of two or more substances without fixed proportions and without chemical bonding
Each substance keeps its original properties
heterogeneous mixture, is a type of mixture in which the components are not evenly distributed throughout the mixture
what is a chemical bond
attraction bw atoms that allow the formation of chemical substances containing 2 or more atoms
what are covalent bonds
Bonding b/w nonmetals
not involved in durg receptor interaction
form when two atoms share one or more pairs of electrons to achieve a stable electron configuration.
Example: Carbon (C) and Oxygen (O)
C:H or C-H
covalent bond
holds together proteins, carbs, & lipids
strongest & most stable chemical bond
covalent bond
what is a hydrogen bond
between positive hydrogen atom and electronegative atom (oxygen, nitrogen, or sulfur)
weakest
any molecule that has a hydrogen atom attached directly to oxygen or nitrogen is capable of this bonding
these molecules in hydrogen bonding have higher boiling points than similar sized molecules that do not have -O-H or an -N-H group
true
this bonding makes molecules sticker and more heat is needed to separate them
hydrogen bonding
Hydrogen bonds perform critical functions in the body, including:
Holding the two strands of the DNA double helix together
Holding polypeptides together
Helping enzymes bind to their substrate
Helping antibodies bind to their antigen
Helping transcription factors bind to each other
Helping transcription factors bind to DNA
what is ionic bonding
bond bw metal and nonmetal
atoms that have excess electrons (negatively charged atom) are attracted to atoms with deficiency of electrons (positively charged atom)
most effective force in attracting drug molecules to a receptor site
stronger than hydrogen bonds but weaker than covalent bonds
ionic bonds
ex of ionic bonds
Sodium (Na) (alkaline metal) and Chlorine (Cl) = Ionic Bond
Chlorine atom takes an electron from the sodium atom converting the atoms into ions (Na+) and (Cl-), which are now held together by their opposite electrical charge
what is a van der waals bond
when they get too close they repel; when they get further away they attract
these are attractive/repulsive residual forces that occur bw molecules or atomic groups that don’t arise from covalent bone, electrostatic interaction of ions, or ionic groups with one another or with a neutral molecule
most common bond bw atoms
weaker than covalent, ionic or hydrogen bonds
operate only when molecules pass very close ot each other
van der waals
provide a weak force for some drugs and their receptors
van der waals
The bigger the atom or molecule the smaller the Van der Waals’ force
false
What is an oxidation/reduction reaction
family of reactions that are concerned with the transfer of electrons
there is no oxidation reaction without a reduction reaction happening at the same time
loss of electrons = oxidation
gain of electrons = reduction
aka redox
you cannot have one without the other
redox reaction
describe the process of oxidation and reduction - REDOX
metal atoms - characterized by tendency to be oxidized
lose one or more electrons resulting in a positively charged ion = cation
these electrons are not destroyed but gained by the non-metal (that is reduced)
non-metal atoms - gain the electrons lost by the metal
forms a negatively charged ion = anion
atoms that are metal will lose electrons (give them up) and when this happens it is + charge because it has more protons
become cations during oxidation period
atoms of non metal will take them and reduced so they become anions (more electrons)
reduction
some life forms maintain reducing environment within their cells
false
all life forms
what is ros
reactive oxygen species
highly reactive molecules containing oxygen. They are natural byproducts of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis.
what is oxidative stress
condition characterized by an imbalance between the production of free radicals (reactive oxygen species, or ROS) and the body’s ability to neutralize them with antioxidants. This imbalance leads to damage of cells, proteins, and DNA, contributing to various diseases and aging processes
includes free radicals and peroxides
ROS
are two processes believed to go hand in hand (the two evil twins!
oxidative stress and inflammation
oxidative stress and inflammation result in
The aging process
Neurodegeneration
Diseases such as
diabetes
some cancers
aterosclerosis
parkinsons
alzheimers
ros benefits
use by immune system to attack and kill pathogens and it is used in cell signaling
overproduction leads to cell damage
ros
necrosis
passive accidental cell death w/ subsequent inflammation
severe oxidative stress can cause cell death
apoptosis
controlled cell death; active programmed cell death that avoids eliciting inflammation
moderate oxidation can trigger this
There are natural antioxidants that occur in the body as well as antioxidants obtained from food and vegetables
true
naturally produced antioxidant found in plants, animals, fungi, and bacteria that protects cells from toxins such as free radicals
Glutathione
Reduced glutathione (GSH) has
trong electron-donating character
All cells in the body are capable of producing glutathione, but synthesis in the _____ is essential
liver
As electrons are lost, the molecule becomes
oxidized
important protector within the auditory-vestibular system
Glutathione
New otoprotective drug therapies are designed to promote actions of
Glutathione
inflammation is apart of complex biological immune response of vascular tissues to harmful stimuli like
pathogens (bacteria, virus)
physical trauma
chemical trauma (acid spill, etc.)
inflammatory response can stays in heightened response resulting in issues like cancers, reduced immunity etc.
true
why is inflammation necessary
to allow body to destroy invading organisms & repair itself (wound healing)
what is chronic inflammation
pathological condition characterized by continued active inflammation response and tissue destruction
chronic inflammatory process induces
oxidative stress and reduces cellular antioxidant capacity
free radicals can lead to
mutation and DNA damage
Overproduced free radicals react with
cell membrane fatty acids and proteins impairing their function permanently
risk factors of chronic inflammation
Hypoxia (COPD?), obesity, hyperglycemia, and smoking
can be a predisposing factor for some cancers and accelerated aging
chronic inflammation
chronic inflammation believed to play a serious role in a wide variety of age-related diseases including
diabetes, cardiovascular, and autoimmune disorders
one of the triggers for autoimmune disorders
chronic inflammation & high ROS in the body
what are the cardinal signs of inflamation
Redness
Vasodilation
Increased blood flow
Swelling
Edema, caused by accumulation of fluid outside blood vessels
Heat
Increased blood flow to the area
Fever is brought about by chemical mediators of inflammation and contributes to the rise in temperature at the injury site
Pain
Distortion of tissues caused by edema
Chemical mediators of inflammation such as prostaglandins
Loss of function
Because of pain or severe swelling that prevents movement
what are proteins
amino acids
amino acids - how many and type, and how they are shaped is influenced by? how is it determined
genetic composition
how each protein develops is influenced by
genetic composition
to form a covalent bond what do you need
to form an ionic bond what do you need
to form a hydrogen bond what do you need
what are enzymes
catalysts that speed up chemical reactions in cells
almost all enzymes are proteins
molecules at beginning of process of enzyme reactions
substrates
enzyme converts substrates into different molecules
products
enzyme has to unite briefly with at least 1 of the reactant
true
can an enzyme alter its shape to accommodate several substrates
yes
what do a set of enzymes do
determine which metabolic pathways will happen n the cell
examples of enzymes
ex: collagenase, lactase, acetylcholinesterase
molecules decreasing enzyme activity
examples
inhibitors
many drugs and poisons
molecules increasing enzyme activity
activators
what can enzymes be affected by
temp
chemical environment (ph)
concentration of the substrate
commercial use of enzynes
synthesis of antibiotics
Household products use enzymes to speed up biochemical reactions
Enzymes in biological laundry detergent break down protein or fat stains on clothes
Enzymes in meat tenderizers break down proteins making the meat easier to chew
what are receptors
protein molecule embedded in cell surface or in cytoplams that allows for communication bw cell and world outside of cell
allows extracellular molecules (hormones, NT, toxins, drugs) to attach to it that results in a change in the cell function
extracellular molecules = ligands
occurs by ionic bonds, hydrogen bonds & van der waals forces
receptor ligand binding
ex of ligand block receptors that stop responses
calcium channel “blocker” drugs - act like plugs & used to treat hypertension
list of proteins
NT
enzymes
receptors
anything not a part of the clel; outside of the cell
ligand
what are proteins
polypeptide sequences formed from the building blocks of many amino acids
held together by covalent bonds
overproduction of free radicals impairs their function
what are NTs
chemical messenger that carries, boosts, and modulates signals between neurons and other cells in the body
most are released from the axon terminal after an AP has reached the synapse, crosses the synaptic gap to reach the receptor site of the other cell or neuron
reuptake - NT attaches to the receptor site and reabsorbed by the neuron
play major role in everyday life and body functions
more than 100 have been identified
affected by disease or drugs that can cause adverse effects on the body
NT
excitatory effects on the neuron; increases likelihood that neurons will fire an action potential
excitatory NT
inhibitory effects on the neuron; decreases the likelihood neurons will fire an action potential
inhibitory NT
ex of excitatory NT
ex: epinephrine & norepinephrine
ex of inhibitory NT
ex: serotonin & GABA
which NT is lacking in parkinsons
dopamine & acetylcholine?
Some neurotransmitters, such as ____ & ______, can have both excitatory and inhibitory effects depending upon the type of receptors that are present
acetylcholine and dopamine
fight or flight response
epinephrine - adrenaline
which disease is seratonin involved in
depression
voluntary movement of the skeletal muscles (via the sympathetic pathways)
acetylcholine NT
wakefulness or arousal - via the sympathetic pathway
norepinephrine NT
voluntary movement and motivation, “wanting”, pleasure, associated with addiction and love
dopamine NT
memory, emotion, wakefulness, sleep and temperature regulation (association with depression?)
serotonin
(5-hydroxytryptamine or 5-HT) –
seratonin
inhibition of motor neurons; major inhibitory neurotransmitter in the central nervous system
Gamma-aminobutyric acid (GABA)
spinal reflexes and motor behavior
glycine
excitatory stimulation
glutamate
what are hormones
chemical substance (peptide or steroid) produced and released by one set of cells and conveyed by the bloodstream to another to affect physiological activity like like growth or metabolism
produced in one area and goes to another as chemical messengers
powerful and only a small amount is needed to alter cell metabolism
hormones
examples of hormones
thyroid hormone, cortisol, estrogen, and testosterone
where are growth hormones produced
thyroid
what hormone is used in audiology
corticosteroids
What are neuromodulators
substance other than a NT that is released by a neuron and transmits information to other neurons that alters their activities
produce diffuse response and released throughout the CNS
play role in sensory transmission especially pain
play role in sensory transmission especially pain
neuromodulators
substance P modulates
pain
dopamine and nicotine are involved in addiction (NT as well as neuromodulators)
true
what is histamine
Organic nitrogenous compound involved in local immune responses - allergies
A group of hormone-like lipids compounds made at the site of tissue damage or infection
They are involved in dealing with injury and illness
prostaglandins
prostaglandins involved in dealing with injury and illness, controlling processes such as
Inflammation
Blood flow
Formation of blood clots
Induction of labor
