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Biology 6, Lecture 1, Sierra College, Badaracco
Lecture flashcards through lecture exam 1.
66
Physiology
Undergraduate 2
08/30/2010

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Cards

Term
Physiology
Definition
What is the study of biological function?
Term
Homeostasis
Definition
What is the maintenance of a stable internal environment?
Term
Levels of Organization
Definition

What is this, "Organism↔Organ System↔Organ↔Tissue↔Cell↔

Organelle↔Molecule↔Atom↔

Elementary Particle," called?

Term
The Law of Maximum and Minimum
Definition
What is the scale where a homeostatic factor is measured on a scale by functional efficiency (ie min, max, stress, death, normal, optimal)?
Term
What is the Basic Feedback Mechanism Describe what each step means.
Definition

Stimulus→Receptor→Modulator→Effector→Response

                          ↑                                                                      ↓

                           ←    ←    ←    ←    ←    ←    ←    ←   ←   ←

Stimulus- A factor that is regulated by homeostasis

Receptor- A tissue or cell

Modulator- Control center

Effector- A musscle or gland

Response- The reaction to the stimulus (release of a hormone or action potential.

 

Term
What is a Negative Feedback System?
Definition
A feedback mechanism in which the response feeds back into the stimulus canceling or counteracting the pathway.  It is seen commonly in the body
Term
What is a Positive Feedback System?
Definition
A feedback mechanism in which the response amplifies the stimulus.
Term
What are some examples of a negative feedback system?
Definition
fluid pH, ion balance, body temperature, etc.
Term
Which is more common in the human body... the positive feedback mechanism or the negative feedback mechanism?
Definition
the negative feedback mechanism
Term
What are some examples of a positive feedback mechanism?
Definition
contractions during childbirth
Term
What are the ways in which homeostatic control is executed?
Definition
  1. Extrinsic- controls come from the outside of the organ by either the nervous system (fast acting/fast to wear off) or the endocrine system (slow acting/slow to wear off)
  2. Intrinsic- controls (chemicals) are made within the organ that is being regulated
Term
What is a physiological rhythem?
Definition
A biological time clock that is regulated by homeostasis. Stimuli from the environment trigger certain aspects of these clocks and the most important in these processes is the hypothalamus.
Term
Give some examples of physiological rhythms.
Definition
sleep, blood pressure, body temperature, food consumption
Term
Define Desynchronosis. What are some causes and effects?
Definition
One or some of the body's physiological rhythms get out of sync. Causes can be jet lag, radical sleep schedules, rotations of work shifts. The effects are foggy head, decreased visual activity, decreased cognitive function.
Term
Describe the basic structure of the cell membrane.
Definition
It is a "lipid bilayer" that contains roughly 50% lipid and 50% protein. The lipid is made up of phospholipid and the protein can consist of either integral (70%) or peripheral (30%) proteins.
Term
What are the functions of the cell membrane?
Definition
It functions to separate the outside of the cell from the cytoplasm, control what gets in and what leaves, and perform a variety of communications between other cells (or to respond to hormones through a homeostatic pathway).
Term
What can enter and exit the plama membrane (without using a protein for assistance)?
Definition
The plasma membrane is semipermiable which means that only certain molecules are allowed to enter and exit. Molecules that are small, non-polar & hydrophobic, and water can pass freely through based upon their concentration gradients. Molecules that are large, polar & hydrophilic (water exculded), and ions have to find other means of entering and exiting the cell.
Term
Carrier Proteins
Definition
Made of at least two molecules, these have a binding site that when activated triggers a "conformational change" that allow substances to enter or exit the cell. It is spesific to what can fit through the entrance=SPECIFICITY. Sometimes a close fit will make it through which means you have two molecules competing for the same site=COMPETITION.
Term
Channel Proteins
Definition
A gated, water filled pore that when opened by a chemical or charge (electrical) will allow the passage of small ions, or small polar molecules. Chemical regulated channel proteins have a binding site. The amount of binding time depends on a number of factors including the chemical, the temperature, etc.
Term
Carrier Mediated Transport
Definition
A passive transport process that allows larger molecules to pass through the cell membrane.
Term
What are some concepts to consider in terms of the random movement of molecules?
Definition
  • Molecules are in a constant state of motion
  • Molecules are constantly striving toward equilibrium
  • The speed of the molecules depends on the temperature.
Term
What is Simple Diffusion?
Definition
A process in which a molecule moves from an area of high to low concentration. An example would be the diffusion of hydrophobic molecules directly through the plasma membrane.
Term
What is Osmosis?
Definition
A passive process when a solvent (usually water) diffuses from an area of low solute concentration to high solute concentration.
Term
Name the five types of vesicular transport. Is this an active or passive process?
Definition
Phagocytosis, endocytosis, pinocytosis, receptor mediated endocytosis, and exocytosis. These are active processes.
Term
What is osmotic pressure?
Definition
The solvent pressure measured on one side of a membrane when there are varying amounts of solute on each side.
Term
What kind of solution is the result of crenation?
Definition
Hypertonic
Term
What kind of solution causes a cell to swell and possibly explode?
Definition
Hypotonic
Term
A cell is in a plasma like solution and at equilibrium. What kind of solution would you call this?
Definition
Isotonic
Term
What is Facilitated Diffusion?
Definition
A passive process in which a carrier protein is used to move a solute from high to low concentration into or out of a cell.
Term
What is Filtration?
Definition
A passive process in which hydrostatic pressure pushes particles through a filterfrom an area of higher pressure to an area of lower pressure. (i.e. the glomerulus in the kidneys)
Term
Give an example of Primary Active Transport.
Definition
Primary Active Transport is when a carrier is used to move solute against its concentration gradient into or out of a cell, requiring ENERGY. An example would be the, "sodium/potassium pump."
Term
What is the difference between chromatin and a chromosome?
Definition
Chromatin is the diffuse, unwound DNA including the regulatory proteins while Chromasomes are condensed and tightly wound. Chromasomes can be viewed with a light microscope while chromatin can not.
Term
What is Secondary Active Transport? Give two examples. Also, why do these go under the active transport category when these items are going with their concentration gradients?
Definition
Secondary active transport is a process in which a sodium ion binds to a carrier protein to open a channel so that a larger molecule may enter or exit the cell. The two examples are Symport and Antiport. The reason that it is an acive process is that the sodium ion must be actively pumped out later.
Term
Why do cells duplicate their DNA? Why do cells make RNA?
Definition
DNA is made during the process of either mitosis or meiosis while RNA is made to code for a protien made in the cytoplasm (the DNA can't leave the nucleus).
Term
What is a gene?
Definition
A gene is a segment of DNA that codes for the order of a spesific polypeptide. RNA must be made before that spesific polypeptide can be put together.
Term
DNA and RNA are what? What repeating units make up their structure and what are these made of?
Definition
DNA and RNA are Nucleic Acids. They are polymers made up of repeating nuleotide units. Each nucleotide consists of a sugar (ribose or deoxyribose), a phosphate, and one of five base groups depending on whether the molecule is DNA or RNA.
Term
Name the base groups of DNA. Which do these pair with?
Definition

Adinine=Thymine

Guanine=Cytosine

 

Term
Name the base groups of RNA. What do these pair with when transcribing the DNA?
Definition

Adinine=Uracil

Guanine=Cytosine

Term
Adinine and Guanine are called?
Definition
Purines
Term
Cytosine, Thymine, and Uracil are called?
Definition
Purimadines
Term
Describe the basic structure of DNA.
Definition
DNA is a double helix that is antiparallel with complimentary base pairs. The rungs consist of a deoxyribose, phosphate, deoxyribose, phosphate... and the sequence of base pairs code for genes.
Term
Why is replication considered "semiconservative"?
Definition
One of the strands comes from the old set and one is newly made from new nucleic acids.
Term
Describe the process of DNA replication/synthesis.
Definition
  1. DNA Helicase and DNA Polymerase unwind and unzip the DNA.
  2. DNA Primase produces an RNA primer for DNA polymerase to start replication.
  3. Deoxyribonucleotide triphosphates align with complimentary base pairs to form hydrogen bonds (steps of the ladder).
  4. DNA Polymerase makes covalent bonds between each sugar and phosphate (rungs of the ladder).
Term

Describe the basic structures of all three RNA molecules.

Definition
  1. mRNA is a single helix shape that has a ribose/phosphate backbone and contains nucleotide base pairs.
  2. tRNA is a molecule that contains an amino acid binding site and an anticodon.
  3. rRNA is a molecule that can either be 40s or 60s (large or small) portion of a ribosome. When these two structures come together with mRNA, translation occurs.

 

Term
How does the genetic code work? What is some basic information that an physiology student should know about it?
Definition
DNA is based upon triplet bases. Each triplet codes for a specific amino acid. Sometimes multiple triplets code for the same amino acid. There are 64 combinations that code for specific amino acids and 3 that mean "stop." The start codes for methionine and it is usually spliced off post-translation.
Term
What is the process in which tRNA is synthesized?
Definition
A RNA structure transcribed by RNA polymerase III (this enzyme is taken to the promoter site on DNA and ends at the termination site), spliced into spesific pieces in post-transcriptional modification and put back together to form a tRNA molecule. This then goes into the cytoplasm to start its job.
Term
What is the process in which mRNA is made?
Definition
RNA polymerase II is taken to the promoter site on DNA and transcribes a copy until it reaches the termination site. The DNA snaps back together and the mRNA goes through post-transcriptional modification. Once the remaining pieces are put back together in the proper order, it travels to the cytoplasm where it can be translated.
Term
What is the process in which rRNA is made?
Definition
There are two forms of rRNA. There are small and large ribosomal subuinits. It starts when RNA polymerase I goes to the promoter site on DNA and transcribes to the termination site. The DNA snaps back together and the rRNA goes through post-transcriptional modification. These pieces then are made into small and large ribosomal subunits that can now travel to the cytoplasm.
Term
Describe the steps involved in translation.
Definition
  1. Initiation- mRNA has undergone post-transcriptional modification and now moves to the cytoplasm. tRNA gets charged with an amino acid spesific to that tRNA by ATP and synthase enzyme. The tRNA binds rRNA (40s) with met (UAC anticodon). The 40s combination, mRNA and 60s rRNA subuints combine to form a single structure.
  2. Elongation-Enzymes peptidyl transferase makes the peptide bonds and elongation factors release tRNA so that it can leave the ribosome. The ribosome moves along the mRNA matching each codon with the properly charged tRNA anticodon to form a polypeptide. tRNA enters the A site charged and exits the P site without an amino acid
  3. Termination-mRNA termination codon is reached. mRNA will detach unless a polysome forms and it would then move onto the next ribosome. Enzymes will then "trim" the polypeptide in spesific places. Even without more modification, the polypeptide does have a shape unique because of the polarities and types of molecules involved.
Term
What are introns and exons?
Definition
Introns are the spliced pieces of RNA after post-transcriptional modification that are not used in the final molecule while Exons are the spliced pieces that are actually used in the RNA molecule.
Term
What are "Free Ribosomes"?
Definition
They are subunits loose in the cell's cytoplasm that are not on the ER. Most protein synthesis occcurs on the Rough ER, but this shows that it can occur in other areas of the cell.
Term
What is a polysome?
Definition
A line of ribosomes using the same mRNA to make multiple polypeptides at once.
Term
What do we need to remember about Thermodynamics?
Definition
Energy is never created or destroyed, it just changes form. Eventually all energy is converted to heat.
Term
What is Entropy?
Definition
It is basically the fact that everything moves from order to disorder. For example, a glass of water is very ordered. If you drop it on the floor it shatters into a million pieces and becomes disordered increasing the Entropy in the universe.
Term
What is potential energy?
Definition
Energy due to positon. (Rock at the top of a hill, water held back by a dam, etc.)
Term
What is kinetic energy?
Definition
Energy due to motion. (chemical rxns, lightning, combustion rxns, etc.)
Term
Name five types of chemical rxns (in a physiological sense).
Definition
Endergonic, Exergonic, Decomposition, Synthesis, Reversible
Term
What are enzymes? Describe what enzymes do from an energy perspective.
Definition
Enzymes are proteins that act as biological catylists. They have a binding site, work quickly, and can be recycled. If they work with other enzymes they can form pathways. From an energy perspective they lower the activation energy of chemical reactions so that the rate of the reaction increases.
Term
What kinds of factors can effect enzyme efficiency?
Definition
  1. Concentration- of both the number of enzymes or substrate
  2. pH and Temperature- enzymes work best in a spesifc range (see the law of max and min)
  3. Inhibitors- can block or change the shape (allosteric site) of an active site so that substrate can't be modified.
  4. Competition- Different subtrates can have a similar shape and compete for the same active site on an enzyme.
Term
What are coenzymes?
Definition
Non-protein, organic molecules that come from vitamins in one's diet. They help to catylize a variety of chemical rxns. Examples include NAD, FAD, And CoA.
Term
What is Adenosine Triphosphate?
Definition
Also called ATP, it is basically and adinie, ribose and three phosphate groups. The third phosphate's bond is highly unstable and the breaking of this bond yields high energy. In the cell it is used for membrane transport, mechanical work, and synthesis of new molecules.
Term
Name some energy molecules other than ATP.
Definition
GTP, ITP, UTP, CTP, Creatine Phosphate
Term
How much energy does one ATP molecule have?
Definition
7.3 kcal/mole
Term
What is Cellular Metabolism?
Definition
The energy sum of all chemical rxns in the body.
Term
What is the differnce between anabolism and catabolism?
Definition
Anabolism is a pathway involving the synthesis of new molecules using energy. Catabolism is a pathway involving the destruction of molecules and the breaking of these bonds gains energy.
Term
What are the differences between aerobic and anaerobic pathways?
Definition
Anaerobic pathways do not use oxygen nor do they require ATP synthesis. Examples of anaerobic pathways include glycolysis, fermination, and substrate phosphorylation. Aerobic pathways require oxygen and synthesize ATP. Examples include the Krebs Cycle, and the Electron Transport Chain.
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