All 02 cards Flashcards
What are the two properties that influence whether a particle can permeate the membrane?
1) Solubility of that particles to lipids. 2) Size of the molecule.
What is the typical movement of Ca+ and Na+ at resting membrane potential?
They flow inward, causing depolarization.
What is osmolarity?
The concentration of osmotically active particles present in a solution.
Why do large and complex animals require a functional cardiovascular system?
Because they have to maintain their high metabolism
Describe temporal summation:
Neurotransmitter are release close together in time.
What are waxes?
Highly nonpolar and impermable compound that are plastic at room temperature.
What is the difference in terms of action between paracrine and endocrine action?
Paracrines are local messengers, cover short distances and are distributed by simple diffusion whereas endocrine action is long distance and rely on the transport of the blood
Describe neurohormones:
Hormones released into the blood by neurosecretory neurons.
Describe monosaccharides
They are single and simple sugar used to assemble larger polymers.
What are the two properties that influence whether a particle can permeate the membrane?
1) Solubility of that particles to lipids. 2) Size of the molecule.
What is osmosis?
The net diffusion of water down its concentration gradient through a selectively permeable molecule.
Describe the mitchondrion
Is where the energy stored in the bonds of carbohydrates and fatty acid is converted into a useful form for the cell.
What are the features found in SOME prokaryotic cells?
1) Cell wall 2) Internal membrane 3) Flagella 4) Fimbriae and pili 5) Cytoskeleton
Describe chemical equilibrium:
Chemical equilibrium is reached when the rate of the forward reaction is equal to the rate of the reverse reaction.
Describe active driving forces:
Require cell to expend energy in the form of ATP to transport substances across the membrane.
What is the general formula of carbohydrates?
Cx(H2O)y. The carbon atoms are bonded with both hydrogen atoms and hydroxyl groups.
State the functions of the lipid bilayer:
1- It forms the basic sctructure of the plasma membrane 2- Its hydrophobic interior serves as a barrier between the inside and the outside of the cell. 3-It’s responsable for the fluidity of the membrane.
Describe the active site in the cleft:
The active site is the region that exhibit the highest degree of complementarity with the shape of the substrate and participate to the strongest interaction with it.
Describe secondary active transport:
Energy is required but not used directly to produce movement against concentration gradient. The transfer of a solute across the membrane is coupled with the transfer of the ion that supplies the driving force.
Describe isolated system:
Isolated system cannot exchange either energy or matter with the sorroundings.
If ΔG=0
The reaction is at thermal equilibrium
What happens a few days before mestruation?
The anterior pituitary begins to increase secretion of FSH and LH.
What’s a substrate?
Substrate is a molecule whose reaction is catalysed by an enzyme.
Describe the structure of hemoglobin:
Is a protein consisting of 4 polypeptide groups sorrounded by a heme group that can reversibly bind to a O2 molecule.
What are the properties of the plasma membrane?
1- Forms the outer boundary of the cell 2- It’s selectively permeable 3- Controls the entrance of nutrients and exit of waste products. 4- Mantain the difference in concentration between the inside and the outside of the cell. 5- Particippiate in the joining of cells to form tissues and organs. 6- Allow cells to interact in different ways with the same extracellular fluid.
What are the two hormones responsable for the correct function of molting in arthropods?
-PTTH -Juvenile hormone
Describe the backbone of DNA and RNA:
Is a chain of sugars and phosphate groups linked by phosphodiester linkages.
Describe antiport:
Solute and Na+ move in opposite directions.
Describe primary active transport:
Energy is directly required to move a substance against its concentrationg gradient.
What is the primary target of ADH?
The kidney
Where are the receptos for lipophilic hormones located?
They can pass through the plasma membrane and bind to specific receptors inside the cell.
What’s energy change?
Energy change is the difference between the energy consumed by the breaking of bonds and the energy release by the formation of bonds.
Describe the characteristics of a closed circulatory system:
It contains the circulatory fluid in a continous system of vessels so that blood cels and large molecules remains in the system while water and small molecules leak out the capillaries.
Describe facilitated diffusion:
It doesn’t require energy and use a carrier to facilitate the transfer of a substance down its concentration gradient.
What are the reasons why oxygen can be obtained more easily from air than from water?
1) O2 content of air is much higher than O2 in water. 2) Diffuses 8000 more rapidly in water than in the air. 3) More energy is required to move water than air because water is more dense.
Describe amino sugars:
An hydroxyl group is replace with an amino group.
What are the three different forms of cell adhesion?
-CAMs -Extracellular Matrix -Specialized cell junctions.
Describe the roles of microfilaments:
1) Allow the cell or part of it to move. 2) Determine and stabilize the cell shape. They are assembled by actin monomers.
Describe sugar phosphate
A phospate group is added to an hydroxyl group.
Describe the 3rd law of thermodynamics:
The entropy, S, of a perfect crystal at the absolute zero is 0.
What are polymers?
Polymers are long molecules constructed by the repetition of simple units called monomers.
What are polymers?
Polymers are long molecules constructed by the repetition of simple units called monomers.
Describe what happens at the half life of 1st order reactions:
For 1st order reaction the half life remain constant with time.
Describe the second law of thermodynamics:
The enthropy of an isolated system increase for any spontaneous change.
Why do only specific target cells respond to a hormone?
Because only target cells have receptors for binding with that particular hormone.
How are monosaccharides divided according to the number of carbon atoms?
-3 carbon sugars (Glyceraldehyde) -Pentoses: They have 5 carbon atoms -Hexoses: Structural isomers with 6 carbons and general structural formula C6H12O6.
Describe the cyclic structure of monosaccharides
The ring structure is more common and stable. It’s formed when the hydroxyl group of the fifth carbon reacts with the carbonyl group. It shows a novel functional group: the hemiacetal group.
What is reduction?
Reduction is gain of electrons.
Describe diffusion down an electrical gradient:
A difference in charge across two adjacent areas promotes the movements of ions toward the area with opposite charge.
What is the diffusion limit?
The rate of a reaction if every collision by a reactant molecule resulted in the reaction producing the product.
Describe spatial summation:
At least two presynaptic neuron fire together and their excitatory presynpatic potential sum up.
Describe the pituitary gland:
Is a small endocrine gland located in a bony cavity at the base of the brain just below the hypotalamus.
What is the function of membrane-bound enzymes?
They control specific chemical reactions.
What’s the half life of a reaction?
The time taken for a concentration of a given reactant to reach half of its value.
Describe inhibition:
An inhibitory synapse has a reverse potential below threshold so it keeps Vm lower.
What are the three major roles of Sertoli’s cells?
-They provide nutrients for the developing sperm. -They form a bloo-testes barrier. -Provide a regulated fluid which allows later stages of development of sperm.
What are thee factors that influce the plasma concentrations of hormones:
1) The hormone rate of secretion into the blood. 2) The rate of metabolic activation or conversion. 3) For lipophilic hormones the extenct of binding to the plasma membrane. 4) Its rate of removal from the blod by metabolic inactivation and excretion in the urine.
How is genetic information encoded in the DNA?
Is encoded as the sequence of bases.
Why are CAMs important?
Because they hepl regulating cell shape, growth and differentiation and allow the cell to adapt to its immediate sorroundings.
Describe the relation between exergonic and endergonic reactions in human body.
In human body, Gibbs free energy released by exergonic reaction is used to force endergonic reactions.
What are the three roles of carbohydrates?
1- They are a source of energy 2- They can transport energy in complex organisms 3- The serve as carbon skeleton for other molecules.
What are the properties of spontaneus reactions?
Spontaneus reaction occurs without the input of energy and once started they proceeds to completion.
What does mestruation marks?
The beginning of both uterine and ovarian cycles.
Describe the peacemaker activity:
The membrane potential slowly depolarize showing a peacemaker potential, until it reaches the threshold and an action potential is then generated.
Describe kinesin:
It carries protein laden vesicles from one part to another walking along a microtubule by a repeated series of shape changes.
If Km is small…
The substrate binds strongly to the active site and the substrate is readily converted to products, even at low substrate concentration
Describe saturated fatty acids:
The alkyl chain contains only C-C single bonds and it’s a straight line. They pack together tightly due to Van der Waals forces and thus they’re solid at room temperature and have higher melting points. Animal fats.
What are the 3 types of system?
1) Open system 2) Closed System 3) Isolated system
What are the three different types of fatty acids?
1-Saturarted 2-Monounsaturated 3-Polyunsaturated
Describe viviparity:
Animals retain the embryo within the mother’s body.
What’s the difference between ribose and deoxyribose?
Deoyribose sugar differs from Ribose sugar in Lacking an Oxygen atom at the 2nd carbon position.
What’s the tendency of ΔS?
ΔS tends to be positive due to random thermal motion at molecular level.
What are the two different kinds of membrane carbohydrates?
Glycoproteins and glycolipids and they form the glycocalix.
Describe the plant cell wall and its major roles:
Is a semirigd structure outside the plasma membrane with 3 major roles: 1) It provides support for the cell and limits its volume by remaining rigid- 2) It acts as a barrier to infection of fungi and other disease causing microorganisms. 3) It contributes to plant form by growing as plant cells grow.
What are the two main functions of excretory organs?
1) Osmoregulation. 2) Secrete waste product while reabsorbing valuable filtered solutes.
What is endocrinology:
The study of homeostatic chemical adjustment and other activites accomplished by hormones.
Why is Km important?
It tells us about the strength of the interaction between the substrate and the enzyme.
What’s work?
Work is energy dispersed as non random motion
How is the ester linkage formed?
Through a condensation reaction between the carboxyl group of the fatty acid and a hydroxyl group of the glycerol.
What are the two types of energy?
1) Kinetic Energy 2) Potential Energy (Gravitational and chemical)
Describe chemoheterotrophs
The energy source of chemoheterotrophs are chemical bonds and the carbon source are organic compounds.
What are the main characteristics of circulation in crocodilians?
-Two complete separated ventricle, they have two aortas. -When is breathing the resistance in pulmonary circulation is low and so all the blood flow in the pulmonary circuit. -When is not breathing polmunary vessles constrict and blood from the right ventricle flow from Aorta.
Describe Glycerophospholipids:
They have a backbone of glycerol just like triglycerides but they differ because one of the three fatty acids is replaced with a phosphodiester group.
State the functions of the lipid bilayer:
1- It forms the basic sctructure of the plasma membrane 2- Its hydrophobic interior serves as a barrier between the inside and the outside of the cell. 3-It’s responsable for the fluidity of the membrane.
What are macromolecules?
Macromolecules are polymers with molecular weight exceeding 1000.
Describe hypertonic condition:
The osmolarity of the inside is lower than the osmolarity of the outside therefore water diffuse out of the cell causing the cell to shrink.
Describe endocytosis:
The plasma membrane pinch-off forming a membrane-enclosed vesicle so that the engulfed material is trapped within the cell.
Progesterone always…
Inhibits
What is the two possible structural configuration of monosaccharides?
-Straight chain -Ring (Cyclic)
What are the roles of the cytoskeleton?
It support the cell and help it maintains its shape. It holds organeless in their position or move them. It interacts with the extracellular structures, helping anchor the cell in place.
What does selectively permeable means?
That the plasma membrane permits some particles to pass through while excluding other particles.
What are the three different kind of polysaccharides?
-Starch -Glycogen -Cellulose
Describe the rate of the reaction:
The rate of the reaction describe how fast does a reaction occurs (how fast the concentration of reactants decrease and the concentration of products increase)
What is a sinatrial node (SN)?
Is a cluster of autorhytmic cells located on the wall of the right atrium where the action potential is generated.
What is the main role of ADH?
To control the amount of fluid loss in the urine.
Describe the function of the posterior pituitary:
Is an extension of the hypotalamus. It doesn’t produce any hormone, it simpy stores and releases vasopressin and oxytocin.
Describe efferent neurons:
Carry instructions to effector organs.
Describe peripheral membrane proteins:
Polar molecules that don’t penetrate the membrane, instead they adhere tightly to the cytoplasmic or extracellular surface.
What are the two kinds of active driving forces?
-Carrier mediated transports -Vesicular transport
What are lipids?
Hydrocarbons insoluble in water because they are non-polar.
Describe oviparity:
The animal lays eggs in the environment and their embryos develop outside their mother body.
Describe vesicular transport:
Requires energy for vesicle formation and movement outside the cell.
Illustrate the cell theory by Schleiden and Schwann
-Cells are the basic structural and physiological units of all organisms. -Cells are both distinct entities and buildin blocks of more complex organisms.
What are the two functions of DNA that constitute the central dogma of molecular biology?
1- DNA can repdroduce itslef (Replication). 2- DNA copies its information into RNA (transcription) and RNA can specify a sequence of amino acids in a polypeptide (translation).
What are channels?
Water filed pathways that serve as conduits that allow water molecules and ions to flow passively through the lipid bilayer.
What are the two kinds of bases?
Pyrimidines (CUT the Pie) and Purines (Pure As Gold).
What is the overall process of sexual reproduction?
Require the joining of two haploid cells (gametes) to form a diploid zygote.
Describe steroids:
Tetracyclic compounds made up of a series of alkyl rings linked by shared carbon.
How are lipophilic hormones transported into the blood?
They cannot dissolve in blood and are therefore bound to specific proteins.
Describe phototrophs in general
Phototrophs capture energy from the sun and use it to oxidise H2O or H2S to release high energy electrons.
Describe anabolism and its characteristics
Anabolism is a process by which large and complex molecules are built up from smaller components. -Biosynthetic and reductive -Energy is required to create bonds -Diverging
Describe dynamic equilibrium:
A dynamic equilibrium which can be described as the probability of molecule being at one state or another at any given time.
What are the two characteristics of oligosaccharides?
They may have additional functional groups which give them special properties and they may be covalently bonded to proteins and lipids on the cell surface acting as recognition signals.
Describe the 1st law of thermodynamics:
The internal energy of an isolated system is constant
What are the 6 events of fertilization?
1) The egg and sperm must chemically recognize each other 2) The sperm is activated, enabling it to gain access to the plasma membrane of the egg. 3) The plasma membrane of the egg fuses with the Plasma membrane of the sperm. 4) The egg blocks entry of additional sperm 5) The egg is metabolically activated and stimulated to start development. 6) The egg and sperm nuclei fuse to create the diploid nucleus of the zygote.
What are the two kinds of bases?
Pyrimidines (CUT the Pie) and Purines (Pure As Gold).
What are the two types of cardiac cells (describe them)
1) Contractile cells: don’t initiate the action potential and they do the mechanical work of pumping the blood out. 2) Autorhythmic cells: don’t contract, they initiate and conduct the action potential and they display a peacemaker activity.
What are the two forms of active transport?
-Primary active transport -Secondary active transport
What are the two types of passive forces?
-Diffusion down a concentration gradient -Diffusion down an electrical gradient
Describe Na+-K+ pump roles:
-It helps estabilish the Na+ and K+ concentration gradient across the plasma membrane. -It regulates the cell volume by controlling the concentration of solutes inside the cell. -The energy used to drive the pump indircetly serves as energy for secondary active transports.
Describe cell adhesion molecules (CAM)
They can either protrude from the outer membrane surface and form hooks and loops or span the plasma membrane where they serve as structural link between the outer membrane surface and its extracellular sorroundings.
Describe flagella in prokaryotic cells:
A complex motor protein spins a flagellum made of flagellin on its axis like a propeller.
How are marine fishes compared to their environment?
They’re hyposomotic which means higher internal concentration of water but lower internal concentration of salt. Salt will tend to diffuse into the body whereas water will tend to flow out.
If ΔG is negative…
The reaction is spontaneous
What is a nucleotide?
A unit of the polynucleotide composed of a nucleoside (a sugar and an amino base) and a phosphate group.
Describe ammonia:
Is toxic, freely soluble in water and easily removed across skin and gills in aquatic animals.
What’s sorrounding?
Sorrounding is everything else in contact with the system.
Describe monosaccharides
They are single and simple sugar used to assemble larger polymers.
Describe photoheterotrophs
The energy source for photoheterotroph is the sun and the carbon source are organic compoounds.
What are transmembrane proteins?
They are integral proteins that extend through the entire thickness of the lipid bilayer one or several times.
Describe the function of dynein:
Motion of cilia and flagella results from the sliding of the microtubules doublets past each other and this movement is driven by dynein.
Where is the AP conducted once is generated?
-It is conducted across the atrium through using the interatrial pathway. -It is conduceted across the ventricles through th atriventricular line.
What is summation?
Graded potential can summate to reach threshold.
Describe the outer membrane of mitochondria
The outer membrane is permeable to most molecules and this is why the intermembrane space has similar characteristics to the cytoplasm.
What are polysaccharides?
Polymers of hundreds or thousands of monosaccharides.
Describe the anterior pituitary:
Consists of glandular epithelia tissue which are then released in response to hypophysiotropic hormones.
Describe chemotrophs in general:
Chemotrophs oxidise organic compounds to release high energy electrons.
What’s Michaelis Constant (Km)?
Is the concentration of substrate required for an enzyme to operate at half its maximum velocity.
What are the four kind of biomolecules?
-Proteins -Carbohydrates -Lipids -Nucleic Acid
What are the three different kind of polysaccharides?
-Starch -Glycogen -Cellulose
What are docking marker acceptors?
They are located on the inner membrane surface and allow the docking of vesicles for exocytosis
Describe the third stage of metabolism:
The acetyle group of Acetyl CoA enter the Kreb’s cycle where it is completely oxidise to CO2 and H2O.
What are the 5 parameters that affect Flick’s Law of Diffusion?
1) The magnitued of the concentration gradient 2) The surface of area across which diffusion takes place 3) The lipid solubility of the substance. 4) Molecular weight of the substance 5) Distance through which diffusion must take place (thickness of the membrane).
What does bond breaking do?
Bond breaking consumes energy
What’s Boltzman probability?
Is the probability that the system will have an enthalphy H at a specific temperature T.
What are nucleic acids?
Polymers of four different kinds of nucleotide specialized in the storage and transmission of genetic information.
Describe starch:
Is a polysaccharide of glucose linked by α-glycosidic linkages. It’s the principal energy storage in plants.
What are the three ways to describe oxidation?
1) Oxidation is joining with an Oxygen 2) Oxidation is losing an hydrogen 3) Oxidation is losing an electron
What are the four kind of biomolecules?
-Proteins -Carbohydrates -Lipids -Nucleic Acid
Why are the chains of fatty acids hydrophobic?
Because they contain C-H and C-C bonds which have low electronegativity and are nonpolar.
What are the two forms of active transport?
-Primary active transport -Secondary active transport
If ΔH is positive…
If ΔH is positive the reaction is endothermic, the system acquire energy and become less stable.
What are the 3 means of control of hormone secretion:
1) Negative-feedback control. 2) Neuroendocrine reflexes 3) Diurnal (circadian) Rhythms.
What are the 5 functions of the extracellular matrix:
1) Holds the cell tissue in position. 2) It contributes to the physical properties of cartilage. 3) It helps filter materials passing between different tissues. 4) It helps orienting the cell movements during embryonic development. 5) It plays a rle in chemical signalling between cells.
Describe regeneration:
Pieces of organism can regenerate complete individuals
What’s endergonic reaction?
A reaction that requires Gibbs free energy (ΔG>0). It’s non spontaneous and reactants favored.
What is an action potential?
A sudden change in Vm due to movement of ions.
State three aspects that affect the efficiency of these transport:
1) Specificty 2) Saturation 3) Competition
What happen in case of water deprivation?
Water deprivation results in an increase in osmolarity which stimulate the hypothalamus to produce more ADH.
What does Enthalphy measures?
Enthalpy measures the energy change in a system.
What’s a phosphodiester group?
Is a phosphate group modified by the addition of different substituent group.
Describe desmosomes:
Adhering jucntions that anchor cells together.
What are oligosaccharides?
Polymers of 3 to 20 simple sugars.
What happens to phospholipids in acqueous environment?
They thend to form a lipid bilayer.
What happens during the first 12 days of ovarian cycle?
Estrogen exerts negative feedback on gonadotropin release.
What are the two main kind of hormones based on their chemical classificatio?
1) Hydrophilic 2) Lipophilic
What are the three different type of cell junctions?
1) Tight junctions 2) Gap Junctions 3) Desmosomes.
What are the two forms of carrier-mediated transport:
1) Facilitated diffusion. 2) Active transport.
Describe oxidative phosphorylation
High energy electrons are used to reduce O2 and H2O and this energy is used to create an electrochemical gradient across the membrane that then generates the energy required to synthesise ATP.
How are hydrophilic hormones transported into the blood?
They simply dissolve in blood.
What are the two types of respiration?
-Internal respiration: Generate ATP -External respiration: Provides the O2 and remove CO2
If Km is large…
The substrate binds less strongly to the enzyme and needs high concentration of substrate to catalyse effectively the formation of products.
Describe monounsaturated fatty acids:
Their alkyl chain contains one C=C double bond that causes the structure to bend.
What are the two units that constitute a desmosome:
A pair of plaques and a strong filament containing cadherin that extend across the space between the two cells attaching the plaques at both sides.
What’s a phosphodiester group?
Is a phosphate group modified by the addition of different substituent group.
Describe statistical thermodynamics:
It also consider microscopic properties of matter and it refers to the probabilities of things happening at a molecular level.
What’s internal energy?
Internal energy is the total energy within a system
An inorganic or organic compound or ion that is required by an enzyme before the enzyme can catalyze its reaction is called a…
cofactor
An example of a cofactor is NAD+
Describe vesicular transport:
Requires energy for vesicle formation and movement outside the cell.
If ΔH is negative…
If ΔH is negative the reaction is exothermic, system loses energy and become more stable.
What is neurotransmission?
The process that generates action and graded potential.
Describe compotetition of carrier mediated transports:
Several closelsy related compounds may compoter for the same carriers and the presence of both diminishes the rate of transfer of either.
What are the reason for the drop from 160mmHg to 100mmHg from the atmosphere to the lungs?
1) The airways are moist, the air from the outside become saturated with water reducing the partial pressure. 2) Fresh inspired air is mixed with a volume of air from the previous breath
What are docking marker acceptors?
They are located on the inner membrane surface and allow the docking of vesicles for exocytosis
What are electron carriers?
Are intermediate of redox reaction in the metabolic pathways of the cell.
What are the two stages of the chemiosmotic process?
Electron transport and ATP synthesis *Oxidative phosphorylation).
How is energy stored in the chemiosmotic gradient used to synthesize ATP?
Protons flow back through ATP synthase causing the rotor to turn and such a conformation change lead to ATP synthesis.
How are monosaccharides divided according to the number of carbon atoms?
-3 carbon sugars (Glyceraldehyde) -Pentoses: They have 5 carbon atoms -Hexoses: Structural isomers with 6 carbons and general structural formula C6H12O6.
Describe the 0 law of thermodynamics:
If the body A is in thermal equilibrium with the body B and the body B is in thermal equilibrium with body C then the body A is in thermal equilibrium with the body C.
What are carotenoids?
Lipids that act as light absorbing pigments.
Describe Non-competitive inhibition:
Occurs when binding of an inhibitor affects the catalytic rate rather than the binding affinity of for the substrate. The substrate and the inhibitor bind at different site on the enzyme.
What happens to phospholipids in an aqueous environment?
They tend to form a lipid bilayer with hydrophilic heads pointing outward. The water is excluded from the hydrophilic core.
Describe endocytosis:
The plasma membrane pinch-off forming a membrane-enclosed vesicle so that the engulfed material is trapped within the cell.
Describe the peculiarity of the outward movement of K+
It moves outward because concentration gradient exceed electrical gradient.
What are the two types of passive forces?
-Diffusion down a concentration gradient -Diffusion down an electrical gradient
Describe the ascending and descending components of the countercurrent system:
Filtrate in the descending limb become progressively more concentrated as it loses water. The ascending filtrate pumps out salt and become hyposmotic.
Describe the three key steps of spermatogenesis:
1) Initial proliferation of male germ cells into spermatogonia proceeds by mitosis. 2) Primary spermatocytes undergo the first meiotic division to form secondary spermatocyte. 3) Second meiotic division produces four haploid spermatids for each primary spermatocyte.
Describe complementary base pairing:
Thymine will always pairs with Adenine, forming two hydrogen bonds. Guanine will always pair with Cytosine forming three hydrogen bonds.
What is the main function of the contraction of the heart?
It create a pressure gradient required to move blood along the vessels.
Describe paracrines:
Local chemical messengers whose effect is exerted only on neighbouring cells in the immediate sorroundings of the receptors.
What happens if the membrane is permeable to a molecule
Molecules move down their concentration gradient (from high concentration to low concentration).
Why are enzyimes highly specific?
Because the shape of the cleft is complementary to the shape of the substrate so that only the substrate can fit into it.
If reduction potential is less than zero (is negative)…
It means that the reduced form of the compound has lower affinity for electrons than hydrogen.
What’s a reaction mechanism?
A reaction mechanism is an educated guess about the way a reaction occurs
What is the reaction from which macromolecules are usually broken down?
Hydrolisis breaks down polymers to their simple units by adding water to the system (energy is released)
What are the two components of the extracellular matrix:
1) A fibrous protein called collagen. 2) A matrix of glycroproteins.
What is the typical movement of K+ at resting membrane potential?
It flows outward, causing hyperpolarization.
Why are glycogen and cellulose good at storing energy?
Because they can both be hydrolized readily into glucose monomers which is then broken down to release energy.
Describe the electron transport
Electron from NADH enter complex I while electrons from FADH2 enter complex II. Electrons are then handed down from higher to lower redox potentials and finally they are transfere to O2 to form H2O.
What’s Gibbs free energy?
Gibbs free energy is the energy produced which is free to do work.
What are the 5 components of the endomembrane system?
1) The plasma membrane 2) Nuclear envelope 3) Endoplasmic reticulum 4) Golgi Apparatus 5) Lysosomes and vacuoles.
Why are phospholipids amphipathic?
Because the two fatty acids tails are hydrophobic (repel water and tend to aggregate) while the phosphate functional group has a negative electric charge thus it’s hydrophilic.
What is a hormone?
A chemical mediator that is secreted by endocrine cells into the blood, where it is then transported to target cells.
How are freshwater fishes compared to their environment?
They are hyperosmotic which means they have lower internal concentratio of water but higher internal concentration of salt. Water will tend to flow in whereas salt will tend to flow out.
What are Vitamins?
Small molecules that cannot be synthetized by the body and must be acquired in diet.
Describe symport:
Solute and Na+ move in the same direction.
Describe carrier mediated transports:
A carrier protein spans the thickness of the plasma membrane and undergoes specific conformational change that allow the transport of substances.
What are the three ways by which CO2 is transported in the blood?
1) As bicarbonate ions (70%) 2) Binded with hemoglobin (20%) 3) Carried in a solution of plasma (5%).
What are the two roles of the membrane sorrounding the organelles in the eukaryotic cells?
1) Keeps the organelle’s molecules away from other molecules in the cell, to prevent inappropriate reactions. 2) Act as a traffic regulator, letting important raw material into the organelle
Describe desmosomes:
Adhering jucntions that anchor cells together.
What are glycolipids?
Lipids that contain a sugar group instead of a fatty acid.
Why are glycogen and cellulose good at storing energy?
Because they can both be hydrolized readily into glucose monomers which is then broken down to release energy.
Why are phospholipids amphipathic?
Because the two fatty acids tails are hydrophobic (repel water and tend to aggregate) while the phosphate functional group has a negative electric charge thus it’s hydrophilic.
State all the characteristics of RNA;
-Its pentose sugar is ribose. -It has Uracil as a base instead of Thymine. -RNA is single-stranded.
What’s the difference between ribose and deoxyribose?
Deoyribose sugar differs from Ribose sugar in Lacking an Oxygen atom at the 2nd carbon position.
What are the two functions of DNA that constitute the central dogma of molecular biology?
1- DNA can repdroduce itslef (Replication). 2- DNA copies its information into RNA (transcription) and RNA can specify a sequence of amino acids in a polypeptide (translation).
Describe cellulose:
Is a polysaccharide of glucose with β-glycosidic linkages, thus is more stable and an excellent structural component. Is the major component of plant cell wall.
What are waxes?
Highly nonpolar and impermable compound that are plastic at room temperature.
What are macromolecules?
Macromolecules are polymers with molecular weight exceeding 1000.
What are fatty acids?
They are long nonpolar hydrocarbon chains and have an acidic polar carboxyl group.
What are carotenoids?
Lipids that act as light absorbing pigments.
What are glycolipids?
Lipids that contain a sugar group instead of a fatty acid.
State all the characteristics of RNA;
-Its pentose sugar is ribose. -It has Uracil as a base instead of Thymine. -RNA is single-stranded.
What is a glycosidic link?
A glycosidic link is the result of a condensation reaction between a hydroxyl group on one sugar and a hydroxyl group on another sugar.
What is DNA?
Deoxyribonucleic acid, a polynucleotide that encodes hereditary information and passes it from generation to generation.
What are the 4 different kind of carbohydrates according to the number of monomers?
1-Monosaccharides 2-Disaccharides 3-Oligosaccharides 4-Polysaccharides
Describe the cyclic structure of monosaccharides
The ring structure is more common and stable. It’s formed when the hydroxyl group of the fifth carbon reacts with the carbonyl group. It shows a novel functional group: the hemiacetal group.
State all the characteristics of DNA:
1- Its pentose sugar is deoxyribose. 2-It’s double-stranded and the two strands form a double helix and are antiparallel (they run in opposite direction).
Describe monounsaturated fatty acids:
Their alkyl chain contains one C=C double bond that causes the structure to bend.
Why are the chains of fatty acids hydrophobic?
Because they contain C-H and C-C bonds which have low electronegativity and are nonpolar.
What are the three roles of carbohydrates?
1- They are a source of energy 2- They can transport energy in complex organisms 3- The serve as carbon skeleton for other molecules.
What are the other roles for nucleotides?
-ATP (Energy transducer in biochemical reactions) -GTP (Energy source in protein synthesis) -cAMP (Essential to the action of hormones and transmission of information in the nervous system).
Describe chitin:
A polymer of N-acetylglucosamine.
Describe glycogen:
Is a polysaccharide of glucose and the form of energy storage in animals. Is water-insoluble and resist osmotic pressure.
What are nucleic acids?
Polymers of four different kinds of nucleotide specialized in the storage and transmission of genetic information.
What are lipids?
Hydrocarbons insoluble in water because they are non-polar.
State the three different types of carbohydrates that can be obtained when a functional group is added:
1-Sugar phosphate 2-Amino sugar 3-Chitin
What are fatty acids?
They are long nonpolar hydrocarbon chains and have an acidic polar carboxyl group.
What are the two possible ways in which complementary base pairing can occur in RNA?
1- Between different regions of the same RNA polymer. 2-Between RNA and DNA (Adenine will pair with both thymine and uracil).
What are the two possible ways in which complementary base pairing can occur in RNA?
1- Between different regions of the same RNA polymer. 2-Between RNA and DNA (Adenine will pair with both thymine and uracil).
State the three different types of carbohydrates that can be obtained when a functional group is added:
1-Sugar phosphate 2-Amino sugar 3-Chitin
Describe sugar phosphate
A phospate group is added to an hydroxyl group.
Describe amino sugars:
An hydroxyl group is replace with an amino group.
Describe saturated fatty acids:
The alkyl chain contains only C-C single bonds and it’s a straight line. They pack together tightly due to Van der Waals forces and thus they’re solid at room temperature and have higher melting points. Animal fats.
State all the characteristics of DNA:
1- Its pentose sugar is deoxyribose. 2-It’s double-stranded and the two strands form a double helix and are antiparallel (they run in opposite direction).
Describe the backbone of DNA and RNA:
Is a chain of sugars and phosphate groups linked by phosphodiester linkages.
What are the three different types of fatty acids?
1-Saturarted 2-Monounsaturated 3-Polyunsaturated
What are the other roles for nucleotides?
-ATP (Energy transducer in biochemical reactions) -GTP (Energy source in protein synthesis) -cAMP (Essential to the action of hormones and transmission of information in the nervous system).
What are triglycerides?
Compound composed of the three carbon alcohol glycerol linked to three fatty acids via ester linkages.
Describe chitin:
A polymer of N-acetylglucosamine.
What are Vitamins?
Small molecules that cannot be synthetized by the body and must be acquired in diet.
What are the 4 different kind of carbohydrates according to the number of monomers?
1-Monosaccharides 2-Disaccharides 3-Oligosaccharides 4-Polysaccharides
Describe glycogen:
Is a polysaccharide of glucose and the form of energy storage in animals. Is water-insoluble and resist osmotic pressure.
What is the reaction from which macromolecules are usually formed?
Condensation reactions assemble polymers from monomers forming a covalent bond and releasing water. (energy is added to the system)
What is the reaction from which macromolecules are usually broken down?
Hydrolisis breaks down polymers to their simple units by adding water to the system (energy is released)
Describe complementary base pairing:
Thymine will always pairs with Adenine, forming two hydrogen bonds. Guanine will always pair with Cytosine forming three hydrogen bonds.
What are polysaccharides?
Polymers of hundreds or thousands of monosaccharides.
What is the general formula of carbohydrates?
Cx(H2O)y. The carbon atoms are bonded with both hydrogen atoms and hydroxyl groups.
What are disaccharides?
Two simple sugars linked by covalent bonds (Glycosidic linkages).
Describe starch:
Is a polysaccharide of glucose linked by α-glycosidic linkages. It’s the principal energy storage in plants.
What are disaccharides?
Two simple sugars linked by covalent bonds (Glycosidic linkages).
What is a nucleotide?
A unit of the polynucleotide composed of a nucleoside (a sugar and an amino base) and a phosphate group.
What are oligosaccharides?
Polymers of 3 to 20 simple sugars.
What happens to phospholipids in an aqueous environment?
They tend to form a lipid bilayer with hydrophilic heads pointing outward. The water is excluded from the hydrophilic core.
What’s a phosphodiester linkage?
The phosphate group links carbon 3’ of one sugar to carbon 5’ of another sugar).
What is the two possible structural configuration of monosaccharides?
-Straight chain -Ring (Cyclic)
What’s a phosphodiester linkage?
The phosphate group links carbon 3’ of one sugar to carbon 5’ of another sugar).
What is DNA?
Deoxyribonucleic acid, a polynucleotide that encodes hereditary information and passes it from generation to generation.
How is the ester linkage formed?
Through a condensation reaction between the carboxyl group of the fatty acid and a hydroxyl group of the glycerol.
What are the two characteristics of oligosaccharides?
They may have additional functional groups which give them special properties and they may be covalently bonded to proteins and lipids on the cell surface acting as recognition signals.
What are triglycerides?
Compound composed of the three carbon alcohol glycerol linked to three fatty acids via ester linkages.
What is a glycosidic link?
A glycosidic link is the result of a condensation reaction between a hydroxyl group on one sugar and a hydroxyl group on another sugar.
How is genetic information encoded in the DNA?
Is encoded as the sequence of bases.
Describe cellulose:
Is a polysaccharide of glucose with β-glycosidic linkages, thus is more stable and an excellent structural component. Is the major component of plant cell wall.
What is the reaction from which macromolecules are usually formed?
Condensation reactions assemble polymers from monomers forming a covalent bond and releasing water. (energy is added to the system)
Describe steroids:
Tetracyclic compounds made up of a series of alkyl rings linked by shared carbon.
