Physiology Exam 1 Study Guide
apical - side of the cell that faces the lumen (interior side of an organ)
basolateral - side of the cell that faces the exterior, away from organ ‘contents’ paracellular - between cells
transcellular - across cells
lumen - inside space and contents of an organ (stomach would be stomach acid and food) basement membrane - the extracellular matrix for the epithelial cells
homeostasis - maintenance of physiological equilibrium. Body’s regulation of its parameters to keep up with a steady internal environment
negative feedback - presence of the end product reduces the rate of production of itself positive feedback - presence of the end product increases the rate of production of itself feedforward regulation - body responds in preparation of an environmental change apoptosis - programmed cell death
aquaporins - membrane proteins that allow water across
rate limiting reaction - step in a process that is responsible for the rate of the entire process. This will be the slowest step in the series
activation energy - the energy input required to make a reaction begin
end product inhibition - the product of a reaction inhibits the enzyme that created it substrate - the material that an enzyme acts upon
active site - part of an enzyme that binds to something else to make a reaction occur ligand - binding chemical
penetrating solute - can cross the cell membrane
nonpenetrating solute - cannot cross the cell membrane
covalent modulation - change to an enzyme that involves a chemical reaction and changes the shape of the binding site Don't forget about the age old question of What are the stages of cell cycle?
allosteric modulation - change to a different site on the enzyme, not the binding site neurotransmitter - chemical messengers (amino acids, gasotransmitters, and monoamines) hormone - signaling molecules secreted by glands that regulate activity of organs paracrine messenger - secreted by one cell and diffused short distances to neighboring cells to alter their behavior We also discuss several other topics like How many moles are in 16.5g c? how many atoms of carbon is this?
autocrine messenger - secreted by a cell to trigger changes in its own behavior
kinase - catalyzes phosphorylation
phosphatase - enzyme that removes phosphate groups (dephosphorylyzes) saturation - concentration of a ligand in the area surrounding the active sites competition - number of different ligands that are able to readily bind to an active site transport maximum - the point where continued increase in the concentration of a substance will no longer affect the speed of its transport across the membrane
affinity - how readily the bond between the ligand and the site forms, and how long it lasts tight junction - adjacent cells have a fused membrane on one side
gap junction - a tunnel with a gate that connects the cytoplasm of two adjacent cells desmosome - string-like protruding structures for cell adhesion to adjacent cells glycocalyx - glycoprotein coating for the cell exterior If you want to learn more check out Explain how cognitive psychology came about.
denature - protein shape altered without disrupting any covalent bonds
degrade - protein’s primary structure is altered, so covalent bonds are broken or altered mediated transport - uniport, symport, and antiport. Transport that is controlled by a protein integrated into the membrane
Structures and Processes:
Lipid Structure - fatty acids are the amphipathic building block for lipids. They incorporate a long EVEN amount of Carbons with the necessary Hydrogens and on the end there is an acidic carboxyl group. The words saturated, unsaturated, and polyunsaturated refer to hydrogen saturation of the molecule If you want to learn more check out The temperature increases by 1◦c. how much does it increase in degrees fahrenheit?
We also discuss several other topics like What makes a sample well represented?
• Triglycerides are a glycerol and three fatty acids, which store energy compactly. This is the fat molecule, and it is overall non polar since the polar oxygens are encased • Phospholipids are a glycerol, 2 fatty acids, and a phosphate. These form cell membranes • Steroids are highly lipid soluble and are chemical messengers. They building block is cholesterol, so they are rings as opposed to a chain
Protein Structure - built of amino acids. These are an amino group, joined with a carboxyl group, and any of the ‘R’ residual molecules. Amino acid built molecules are referred to as peptides. The distinction has to do with the size. Proteins are around at least 50 amino acids. Proteins have 3D complexity, and these levels of structure are as follows: • Primary is the pattern of amino acids, how many and in what order
• Secondary is the general group of related sequences form what regular shape. An example is the alpha helix, or spiral that hydrogen bonds form in DNA
• Tertiary is the secondary structure folded onto itself due to R-group interactions • Quantary/Quaternary comes when multiple polypeptides are intertwined
Cell Structure and Function
• cytosol - water and compounds dissolved into it If you want to learn more check out What is the storage form of cho in the body?
• organelles - discreet structures. Non membranous organelles include the cytoskeleton (actin filaments) and ribosomes (free or bound to the endoplasmic reticulum). Membranous organelles include the nucleus, mitochondria, endoplasmic reticulum, golgi body, lysosomes, peroxisomes, and vesicles
• Smooth endoplasmic reticulum shuffles calcium in and out constantly. Short term, manipulated calcium storage. Muscle cells have a lot of this
- This is an example of how different cells have different structures and different amounts of organelles in order to perform their specified function.
• Vesicles can be for storage within the cell, transport to the cell exterior, or can be specialized into lysosomes, which are vesicles that contain digestive enzymes, or peroxisomes, which contain antioxidants to counter free radical oxygens that would degrade our membranes and proteins
Regulation of Proteins
• Transcriptional control - enzymes prevent or catalyze the synthesis of the mRNA copies of DNA that code for the protein
• Translational control - enzymes prevent or catalyze the synthesis of the protein from already existing mRNA copies
• Post translational Modification - change the activity of the protein. Some cases, turns the protein on, while in others it turns it off
- Allosteric modification: two binding sites, regulatory (controls activity) and functional (actual does the job the protein is intended to do). Two ligands: modulator molecule binds to regulatory to alter shape of binding site to activate (increase affinity) or inhibit (decrease affinity) of the controlling protein
- Covalent modulation: requires chemical reaction. another word for phosphorylation and dephosphorylating to deactivate (two separate reactions with two different enzymes involved)
- amount of energy involved is the most notable difference between the two. covalent requires much more energy to make and break bonds as opposed to allosteric being controlled by concentration of reactants and products
• Splitting: polypeptide is cut into pieces to activate or deactivate those pieces. NOT the same as splicing, which happens to mRNA. Splitting is not reversible, meaning if you need the original protein again, it has to be made over again
- Glycosalation & Methylation are modification as well as labeling mechanisms to help the proteins get to the right place in the cytoplasm
• Kinds of control: Translation, splicing, transcription, post translational, degradation - Denaturing acts on many proteins at once, so it isn't considered a control mechanism
Properties of Binding Sites: Binding of a ligand is due to the shape and charge distribution that the correct protein folding allows for. The area where it attaches is called a Binding Site. Changes in the environment alters the binding site and therefore can inhibit or allow attachment of a ligand. The important characteristics of binding sites are the following: • Affinity - measure of how readily the bond between the ligand and binding site is made and how long it lasts
• Specificity - exactness in match of shape and size
• Competition - how many different ligands can readily bind to the site
• Saturation - how much of a particular ligand is available for the site
Reaction Direction: determined by relative concentrations. A change in the concentrations from equilibrium will result in a reaction occurring in one direction or the other
Reaction Rate: determined by the affinity of enzyme for the substrate as well as concentration of the substrate
Enzyme Properties: All enzymes are proteins. The folding of proteins is crucial to their function. Sometimes the folding happens automatically after formation, and sometimes helper proteins have to hold parts in place. The correct environmental conditions are important for proper protein shape and function. Enzymes have no direct effect on a reaction, they only affect speed.
Cellular Respiration: This is the energy transfer from ATP, and it dictates most cellular function. Removal of a phosphate group results in a release of a large amount of energy. The three pathways involved are Glycolysis, Kreb’s Cycle, and Oxidative Phosphorylation. Together they are a pathway for carbohydrates, primarily glucose.
• Glycolysis: glucose is a 6 carbon sugar. It is split into two three carbon molecules. The two 3C’s can be converted into 2 pyruvate. (costs 2 ATP to make, uses 2 NAD+, but produces 2 NADH and 4ATP)
• Kreb’s Cycle: takes place in the mitochondria. Uses oxygen and converts ADP into ATP while producing CO2 and H2O as waste products
• Oxidative Phosphorylation: electron transport chain Solute Transport
**Look up flow charts of these on the internet or in the book. I can’t include any without violating copyright but we need to be able to draw the general systems and identify what is used/made according to our professor**
Tonicity and Cell Shape: the osmotic pressure gradient across the membrane can effect the shape of the cell. There are three main gradient terminologies used:
• Hypertonic - if the cell is in this type of solution, there is a higher ion concentration outside the cell and water tends to flow out of the membrane. This makes the cell shrivel • Hypotonic - if the cell is in this type of solution, there is a higher ion concentration inside the cell and water tends to flow into the cell, causing the cell to overflow and potentially eventually burst
• Isotonic - ion concentration is essentially equal on both sides of the membrane. Pressure does not favor either side of the membrane, so the cell doesn't shrivel or swell
• Stimuli act on Receptors, which by the Afferent Pathway send a signal to the Integrating Center, which organizes the information and sends the appropriate instructions via the Efferent Pathway to the Effector who creates the response
Commonly Missed/Mixed Up: these are explained in our professor’s study guide on Blackboard
Happy studying! I hope you found this study guide useful. This is what I will personally be using to review for the exam, however I would also suggest reviewing the corresponding figures for the information. Feel free to email me with any questions!