Lecture 1 Flashcards
1) Define physiology
2) Define homeostasis. Why is it maintained?
1) Studying the functions of organisms and their parts
2) A highly coordinated balance of chemical and physical systems in the body. Internal environment is tightly regulated to maintain optimal cellular function
The _______system provides an intricate communication network to tissues and organs
neuroendocrine
What does the autonomic system do?
Regulates the body’s internal organs.
What are the 4 types of tissue? Describe each briefly.
1) Connective tissue: supports and anchors body parts
2) Muscle tissue: contracting, generating tension, producing movement
3) Epithelial tissue: exchange materials between cell and environment
4) Nervous tissue: generate and transmit electrical signals
1) What are the two types of secretory glands?
2) What type of tissue are they?
1) Exocrine and endocrine
2) Epithelial tissue
What are the 3 types of muscle?
1) Skeletal
2) Cardiac
3) Smooth
Give 5 examples of things that need to be balanced to maintain homeostasis
1) Oxygen and carbon dioxide tensions
2) Concentrations of glucose and other metabolites
3) Osmotic pressure
4) Concentrations of hydrogen, potassium, calcium and magnesium ions
5) Temperature
1) True or false: Homeostasis is maintained within narrow limits
2) What can disruptions in homeostasis lead to?
1) True
2) Death
What are the two types of feedback loops? Describe each and how common they are
1) Negative: promotes stability, most systems in the body. Feedforward control promotes anticipated change (ex: getting hungry); change in one direction limits change in that direction.
2) Positive: change promotes more change in that direction. Seen in childbirth and cancer.
1) What is required to maintain a steady state and cellular equilibrium?
2) What are the two requirements of cellular equilibrium?
1) Energy
2) Opposing forces are balanced, and there’s no net transfer of a substance or energy
1) What does the plasma membrane primarily consist of? Give 2 examples
2) What 3 types of proteins does the plasma membrane contain?
3) What can bind to plasma protein receptors?
4) How are carbohydrates involved in plasma membranes?
1) Different types of lipids with dissimilar functions
Ex: Phospholipids and cholesterol
2) Integral proteins, peripheral proteins and glycoproteins
3) Ligands
4) Act as “selfie” markers
1) What are phospholipids made of?
2) What part of the cell is constantly moving?
1) A phospholipid head and two nonpolar tails
2) Phospholipids are constantly moving
1) True or false: phospholipids are always moving
2) What is the role of cholesterol in the membrane?
1) True
2) Prevents crystallization
1) Do all cells have the same glycoprotein/ lipid markers?
2) What is the role of glycoprotein/ lipid markers?
1) No, they’re a “trademark” of a particular cell type
2) Restrict overgrowth, regulate cell density
1) What are CAMs? What do they do?
2) List the 2 types of CAMs and what each does
1) Cell adhesion molecules (CAMs) are a type of membrane protein that helps cells stick to each other and the ECM
2) a) Cadherins: act as a zipper
b) Integrins: connect cytoskeleton to ECM
What 3 things do cell-to-cell adhesions rely on?
1) CAMs (cell adhesion molecules)
2) Extracellular matrix
3) Cell junctions
1) Define extracellular fluid
2) Name two types of ECF
3) What does the extracellular membrane (ECM) do?
1) Fluid outside the cell
2) Plasma and interstitial fluid
3) ECM: acts as “biological glue”
What are the 3 types of protein fibers found in the ECM? Briefly describe each
1) Collagen: flexible nonelastic fibers that provide tensile strength
2) Elastin: rubbery protein in stretchy tissues like lungs
3) Fibronectin: promotes adhesion, keeps cells in place
1) What is the most abundant protein in the body?
2) What protein fiber is associated with scurvy? Why?
3) What protein is found in reduced numbers in cancerous tissues?
1) Collagen
2) Collagen; lack of Vit C causes defects in collagen, so tissues become fragile, so skin and mucous membranes bleed
3) Fibronectin
1) What is also known as adhering junctions?
2) What do they do?
3) Where are they present?
1) Desmosomes
2) Act as “rivets” that anchor adjacent non-touching cells
3) In tissues that stretch considerably (like skin, heart, uterus)
1) What is also known as an impermeable junction?
2) What do they do?
2) Where are they found?
1) Tight junctions
2) Claudin proteins fuse the plasma membranes of adjacent cells
3) In sheets of epithelial tissue like the digestive tract
What are the 3 types of connections?
1) Gap junctions
2) Tight junctions
3) Desmosomes
1) What are also known as communicating junctions?
2) What are the links of this junction type? How many are there?
3) Where are they abundant? What moves through them?
1) Gap junctions
2) Linked by tunnels of connexon; 6 protein connexins
3) In cardiac and smooth muscle; ions move through gap junctions
What are the two types of cellular fluid? Describe them
1) Intracellular fluid (ICF): contained within body cells
2) Extracellular fluid (ECF): outside the cells but inside the body
What are the two types of ECF? Describe each
1) Plasma: fluid portion of blood
2) Interstitial fluid: surrounds the cells
What are the 3 primary types of solute transport mechanisms? Briefly describe them
1) Exocytosis: movement of large molecules to outside the cell
2) Endocytosis: movement of large molecules to inside the cell
3) Movement of ions: Passive transport and active transport
Describe passive and active transportation of ions
1) Passive transport: No energy
2) Active transport: Metabolic energy required; works against the electrochemical potential
1) Where are macromolecules synthesized?
2) What packages things for exocytosis?
3) What are those things packed into?
4) Give an example of cells that use exocytosis. What do they use it for?
1) In the endoplasmic reticulum
2) The Golgi apparatus
3) Transport vesicles
4) Goblet cells; for the continuous secretion of mucous in the small intestine
1) Define endocytosis
2) What are 3 types of endocytosis?
1) Endocytosis is the internalization of extracellular material
2) Pinocytosis, receptor-mediated endocytosis, and phagocytosis
1) What does pinocytosis mean?
2) What is the unique part of this process?
3) What is this a type of?
1) “little drink”
2) Dynamin pinches the neck
3) Exocytosis
1) What type of endocytosis is highly selective?
2) What does this type of endocytosis take up?
3) What is the unique part of this process?
1) Receptor-Mediated Endocytosis
2) Cholesterol, B12, insulin, iron
3) Clathrin molecules of the plasma membrane form the pouch
1) What type of particles are eaten in phagocytosis?
2) Which cells are capable of this? Give an example
1) Multimolecular particles (usually bacteria)
2) Only a few cells; WBCs are an example
1) What is autophagy?
2) Why does this happen?
3) Give an example of this
1) A cell eating itself
2) Damaged cells are recycled, but sometimes this process happens when it shouldn’t
3) Tay-Sachs disease in nerve cells; leads to profound neurological degeneration
1) Define Fick’s law
2) What process is this relevant to?
1) Movement of substances is always from a high concentration to a low concentration
2) Passive (simple) diffusion
Give 5 examples of factors that effect the speed of diffusion, and how they effect it
1) Magnitude: larger = faster
2) Surface area: larger = faster
3) Lipid solubility : more = faster
4) Molecular weight: lighter = faster
5) Distance: smaller = faster
How does pneumonia effect diffusion?
Effects distance
1) What facilitates diffusion of solutes across the plasma membrane?
2) What keeps diffusion from being infinitely fast?
3) Describe the rate of simple diffusion. How do facilitators affect this?
1) Integral membrane proteins
2) Limited number of pores, channels, and carriers
3) A steadily increasing rate; affect saturation
1) Define membrane pore. What is allowed through it?
2) What do aquaporins do? Where are they common in the body?
1) A conduit through the lipid bilayer that is always open to both sides, but only allows certain substances.
2) Allow the rapid movement of water; common in the kidney and GI tract
1) When are gated channels useful?
2) How are ligand gated ion channels different from gated channels?
3) Give an example of a ligand-gated ion channel
1) To reset back to homeostasis when something goes wrong
2) Ligand-gated first must bind to a specific agonist, then it produces a conformational change
3) Nicotinic Acetylcholine Receptor channel in postsynaptic neuromuscular junction
1) What does carrier-mediated transport do?
2) Give an example
1) Produces a change in the protein
2) Glucose from the blood to the cells using GLUT1; affinity for D-glucose than L-Glucose
1) Active transport is _______ the concentration gradient
2) What does primary active transport use?
3) What’s one of the most important examples of this?
1) against
2) Ion pumps
3) Sodium-potassium pump
1) What transport and concentrate sodium and potassium? Where does this concentration occur?
2) How many binding sites for sodium and how many for potassium?
3) Which side has an affinity for Na+? What about K+?
1) Carrier proteins; concentrate Na+ in the ECF and K+ in the ICF
2) 3 binding sites for Na+, 2 for K+
3) High affinity for Na+ on the ICF side and K+ on the ECF side
1) Where does the energy come from in secondary active transport?
2) What are the two binding sites of secondary active transport for?
3) What are the two types of ports used in this process?
1) Energy comes from ion moving down its electrical gradient (essentially hijacks the energy from primary active transport)
2) One binding site for the target molecule and one for the ion
3) Symport: two types of molecules in same direction
Antiport: opposite directions
1) What do all human plasma membranes have in common?
2) What are opposite charges separated by?
1) They’re electrically polarized/ have a membrane potential
2) By the membrane, which itself doesn’t have a charge
1) Which moves across cell membranes more, K+ or Na+? Why?
2) What keeps all of this ion from being passively leaked?
1) K+ has many more leak channels for passive transport than Na+ (25-30x more permeable)
2) Nonpermeable proteins in the cell (negatively charged) resist passive leaking of K+ (as does the sodium-potassium pump)
1) What is the main anion of the ECF?
2) What does this anion do?
3) Do cells have transport mechanisms for this?
4) How does Cl- move?
5) What determines the equilibrium potential of Cl-?
1) Chloride is the principal anion of the ECF
2) Maintain equilibrium potential of -70mV
3) Most cells have no transport mechanisms for Cl-
4) Passive diffusion
5) Membrane potential determines the Cl- equilibrium potential
Anions are ______ charged and move towards an area of _______ charge
negatively; positive
1) What moves water across the plasma membrane?
2) What regulates cell volume?
3) What is oral rehydration therapy driven by?
1) A difference in osmotic pressure
2) The osmolality of the extracellular fluid regulates cell volume
3) Solute transport
1) Define tonicity
2) Define isotonic solution and describe its effect on cell volume
3) Define hypotonic solution and describe its effect on cell volume
4) Define hypertonic solution and describe its effect on cell volume
1) The tonicity of a solution is its effect on cell volume
2) Isotonic solutions: same concentration, do not alter cell volume
3) Hypotonic solutions: below-normal solute concentration, cell volume increases
4) Hypertonic solutions: above-normal concentration, cell volume decreases
1) How many ways do cells have to communicate locally? What are they?
2) What allows rapid and targeted communication?
3) What type of communication is slower and more diffuse?
4) How do the nervous and endocrine systems divide their control?
1) By paracrine and autocrine signaling
2) The nervous system coordinating input
3) Endocrine system provides for slower and more diffuse communication
4) They provide overlapping control
1) Define apoptosis
2) What plays a key role in this process?
3) What cells can this occur in? Why?
1) Deliberate cell suicide
2) Mitochondria
3) Every cell has a doomsday trigger called cytochrome c
When is apoptosis needed? (4 scenarios)
1) Normal embryonic development
2) Tissue turnover
3) Immune system
4) Undesirable cells
1) Give an example of a condition that occurs when there’s not enough apoptosis
2) What happens when there’s too much apoptosis?
1) Not enough apoptosis:
Cancer
2) Too much apoptosis:
Alzheimer’s, Parkinson’s
1) What is the largest part of a cell?
2) What surrounds this part?
3) What does this part do?
4) What is contained within this part?
1) Nucleus
2) The nuclear envelope
3) Houses genetic material
4) Nucleolus
What does a nucleolus of a nucleus of a cell contain?
DNA/ 46 Chromosomes
What are the 3 types of RNA?
1) Messenger RNA (mRNA)
2) Ribosomal RNA (rRNA)
3) Transfer RNA (tRNA)
1) What is the most common fatal genetic disorder?
2) What protein is responsible for this?
3) How does the protein cause this this disorder?
4) What two organs are effected?
1) Cystic Fibrosis (CF)
2) Transmembrane conductance Regulator (CFTR)
3) Defective CFTR gets stuck in ER-Golgi system, so the plasma membrane becomes impermeable to chloride
4) Lungs and pancreas
In cellular respiration, molecules are broken down into ATP through how many stages? List them
3 stages:
1) Glycolysis
2) Citric Acid Cycle
3) Oxidative Phosphorylation
1) What does ATP stand for?
2) What is the energy currency of cells?
3) What 3 things is ATP broken down into for cellular use?
1) Adenosine Triphosphate
2) “Energy Currency”
3) Cells split ATP into ADP, phosphate, and energy
________ is the crude fuel of the body, ______ is the refined fuel
4) Food; ATP
During oxidative phosphorylation:
1) Where are electrons transferred?
2) What two things carry hydrogens to the electron transport system?
3) Electron Transport System and ATP synthase: _______ assembly line (**not sure what this means tbh)
1) To oxygen
2) NADH and FADH2 carry hydrogens
3) proton
1) How many ATP does oxidative phosphorylation make per 1 glucose?
2) How much ATP is made per glucose molecule in cellular respiration as a whole?
1) 28 ATP molecules per glucose molecule
2) Total of 32 ATP via all of these processes
What are the two types of cellular energy production? Which is more efficient?
1) Aerobic (with air / O2); more efficient
2) Anaerobic (lack of air / O2)
1) How does cellular production of ATP proceed without O2?
2) What is pyruvate converted to during anaerobic respiration?
1) Without O2, energy production does not proceed beyond glycolysis
2) Lactate
1) What type of exercise uses aerobic processes?
2) What type of exercise uses anaerobic processes? What process is used specifically?
1) Aerobic exercise, which is at a low-enough intensity
where CAC and OP are the primary fuel sources
2) Anaerobic exercise, which is short intense bursts of activities; uses glycolysis
1) Define epigenetics
2) Give examples of things that can effect gene expression
3) Is DNA itself altered in epigenetics?
1) Epigenetics is the study of environmentally induced modifications to gene activity
2) Smoking, diet, stress, etc.
3) DNA itself is not altered, genes are being turned off and on
Give two examples of things that influence diffusion
Distance and surface area
Name one of the two types of cell adhesion molecules (CAMs)
Cadherins (or integrins)
What does hypotonic solution do to a cell?
Cause it to expand
What two things cytochrome c a component of?
1) Apoptosis (as a kill switch)
2) Electron transport system
True or false: ICF and ECF have the same composition
False; Intracellular fluid composition differs from the extracellular fluid composition
1) Is the phospholipid head of the plasma membrane hydrophobic or hydrophilic?
2) Are the phospholipid tails hydrophobic or hydrophilic?
1) Phospholipid head:
Hydrophilic
2) Two nonpolar tails:
Hydrophobic
What part of the cell is collagen found in?
The extracellular matrix (ECM)
What is a “trademark” of a particular cell type?
Glycoproteins/ lipid markers
Describe carrier-mediated transport and give an example
1) Produces a change in the protein
2) Glucose transported from the blood to the cells using GLUT1, which has an affinity for D-glucose over L-Glucose
1) Are cells more negatively charged internally or externally?
2) What is the resting membrane potential of cells?
3) What 3 ions move to maintain a steady state? What allows this to happen?
1) More negatively polarized on the inside compared to the outside
(by how much depends on cell type)
2) -50mV to -90mV
3) Na+, K+ and Ca2+ ; pumps actively move against the gradient to maintain the negative state
1) What does the Nernst equation calculate?
2) What does the Goldman-Hodgkin-Katz equation calculate?
1) Equilibrium potential for a given ion can be calculated by the Nernst equation
2) Membrane potential can be calculated by Goldman-Hodgkin-Katz equation
What two properties make up the electrochemical gradient?
Charge and concentration
(Net effect = electrical + concentration gradient = “electrochemical gradient”)
Describe the citric acid (Krebs) cycle. What is made? How is O2 involved?
1) Yields (x 2) each glucose = 2 pyruvate = 2 acetyl-CoA; 2 CO2, 3 NADH, 1 FADH2, 1 ATP, Repeat
2) O2 is not directly used, but is required for pyruvate to enter the Krebs cycle
O2 is required for ________ to enter the Krebs (citric acid) cycle
pyruvate
What does glycolysis yield? Is it efficient?
1) 2 NADH, 2 pyruvate, 2 ATP
2) Not efficient; only 2 molecules of ATP per glucose molecule
List 3 uses of ATP
1) Synthesizing new compounds
2) Membrane transport against a gradient
3) Mechanical work like cardiac or skeletal muscle
Give 2 examples of compounds cells can synthesize using ATP (produced by cellular respiration)
1) Proteins
2) Secretory compounds
1) What molecule is necessary for oxidative phosphorylation?
2) What molecule is produced primarily by the citric acid cycle?
1) O2
2) CO2
1) What molecule is produced primarily by the electron transport system?
2) What molecule is produced primarily by ATP synthase?
1) H2O/ water
2) ATP
What is the formula for cellular respiration?
Food + O2 <> CO2 + H2O + ATP
What is a marker for how cells identify self?
Carbs
What are the two divisions of the epithelium?
Secretory glands, and sheets
Is sodium more prevalent inside or outside the cell?
Outside (ECF)
Do lipophilic or hydrophilic substances move faster in simple diffusion?
Lipophilic
