Exam 1

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In a blood pressure example, the sensor (blood pressure receptors) are aware of high blood pressure, the integrating center (brain and nerve fibers) convey to the heart (effector) to increase our heart rate. This increase in our heart rate comes with an increase in blood pressure - a change in the opposite direction of the original change.
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Terms in this set (63)
In a blood pressure example, the sensor (blood pressure receptors) are aware of high blood pressure, the integrating center (brain and nerve fibers) convey to the heart (effector) to increase our heart rate. This increase in our heart rate comes with an increase in blood pressure - a change in the opposite direction of the original change.
What is the role of sensor, integrating center, and effector in negative feedback loop?
In a positive feedback loop, the effector amplifies changes that have stimulated the effector in the first place. In childbirth, the pituitary hormone oxytocin is secreted, causing contractions of the uterus, thus sending feedback to the pituitary gland to release MORE oxytocin. Here we see how the effector (pituitary gland) has amplified, rather than reversed, changes that occurred in the body.
Give an example of a positive feedback loop.
An example of negative feedback is sweating. We feel hot (stimulus), which our sensors (temperature receptors in the skin) convey to our brain (also known as integrating center) which conveys to our sweat glands to secrete sweat. This change - sweating - reverses the effect of the original stimulus. This kind of negative feedback is a continuous process within the body.
Give an example of a negative feedback loop.
We observed that the class average 2-point threshold for the thumb was significantly smaller than the average 2-point threshold for the forearm, supporting our hypothesis that thumbs have a lower 2-point threshold and are more sensitive to touch.
How did you support or reject the hypothesis with your 2-pt threshold data? What was the main conclusion?
a weak bond with a positive end (hydrogen) and a negative end (oxygen or nitrogen). attraction is weaker than a covalent or ionic bond
Describe a hydrogen bond
Acids are proton donors; they raise the amount of H+ (acidity) in a solution
How are acids related to protons and acidity?:
Image: Acids are proton donors; they raise the amount of H+ (acidity) in a solution
Bases act as proton (H+) acceptors, decreasing the amount of H+ (acidity) in a solution
How do bases neutralize acids?
Image: Bases act as proton (H+) acceptors, decreasing the amount of H+ (acidity) in a solution
pH is a measure of how much H+, or acidity, is in a solution, with 14 referring to the most basic (least H+) and 0 as most acidic (most H+)
Describe pH scale from 0-14 and how it compares acidic, basic and neutral substances.
Image: pH is a measure of how much H+, or acidity, is in a solution, with 14 referring to the most basic (least H+) and 0 as most acidic (most H+)
Buffers are substances that resist pH change, and help us maintain homeostasis.
Describe how buffers work and help maintain blood pH.
General lipid structure: they are water insoluble, and nonpolar. Triglyercides are 1 class of lipids and include unhealthy saturated fats (includes trans fats which are synthetic saturated fats) & Healthy unsaturated fats. Saturated fats are solid, and unsaturated ones are liquid (think fish oil). General structure of a triglyercide: glyerol plus 3 fatty acids.
Describe general structure of triglyercides
Image: General lipid structure: they are water insoluble, and nonpolar. Triglyercides are 1 class of lipids and include unhealthy saturated fats (includes trans fats which are synthetic saturated fats) & Healthy unsaturated fats. Saturated fats are solid, and unsaturated ones are liquid (think fish oil). General structure of a triglyercide: glyerol plus 3 fatty acids.
When an acid enters the blood, the bicarbonate ions in blood neutralize the hydronium ions, thus forming carbonic acid and water. Carbonic acid is already a component of the buffering system of blood. Thus hydronium ions are removed, preventing the pH of blood from becoming acidic.Practice question: How can carbonic acid cause blood pH to lower?ketone bodies: free fatty acids. they function as energy in an emergency. structure?Describe general structure of ketone bodieshas hydrophilic head and water-insoluble tail. functions as a cell membrane.Describe general structure of phospholipids.can take form of sex hormones like testosterone, cell membrane (cholesterol) or stress hormones like cortisolDescribe general structure of steroids (a form of fat)20 amino acids arranged in a chain.describe basic protein structure. how are amino acids arranged?primary: one strand of amino acids. secondary: helix structure. tertiary: 3-d shape with a helix and heme- group. quaternary: hemoglobin.how are proteins arranged in the 4 structural levels?Get amino acids to build up new proteins such as - Structural proteins - Enzymes (speed up reactions that are occurring already) - Antibodies, Energy if needed.function of proteins? what about enzymes?this is when protein loses its shape. for example, when cooked meat becomes firm because the proteins have lost their shape.denaturationThey speed up reactions, they're proteins, they can be reused, and they denature.what are the traits of enzymes?1. ribosomes bind to mRNA. 2. RNA polymerase makes mRNA. 3. mRNA is edited. 4. mRNA leaves the nucleus.list the stages of protein synthesis in the right order.Nucleotides = building block of nucleic acids. phosphate sugar and bases?compare and contrast the 2 classes of nucleotides with phosphate, sugar, and bases.DNA is a double strand of nucleotides. RNA is a single strand of nucleotides.compare and contrast the 2 classes of nucleic acids: DNA and RNA.-AKA cell membrane/ plasmalemma -semi-permeable barrier -regulates passage of gases, nutrients, and wastes between internal and external cell environmentswhy is the plasma membrane a fluid mosaic model?Phagocytosis (taking in solid particles) and endocytosis (absorbing stuff into cell membrane itself) = stuff moves in membrane. exocytosis = stuff moves out of the membrane.how do substances move in (phagocytosis and endocytosis) and out (exocytosis) of the cell?Cilia are capable of movement"bend and wave" but remain attached to a surface. Flagella are attached to a cell (sperm) propelling "transporting" it somewhere. Microvilli are totally stationary. cytoplasm contains all the organelles in the cell. cytoskeleton is flexible skeleton of cell. mitochondria is powerhouse of cell. ER is involved in protein synthesis. golgi complex packages proteins to be exported from cell. lysosome destroys viruses and bacteria using digestive enzymes. ribosomes bind mRNA and tRNA to make proteins. a peroxisome is a membrane-bound organelle involved in oxidation.review cilia, flagella, microvilli, cytoplasm, cytoskeleton, lysosomes, peroxisomes, mitochondria, ribosomes, endoplasmic reticulum, golgi complexvery full, fast moving, lots of organelleswhat does inside of a cell look like in action (recall protein packing video)Chromosomes are made up of a DNA-protein complex called chromatin that is organized into subunits called nucleosomes. The way in which eukaryotes compact and arrange their chromatin not only allows a large amount of DNA to fit in a small space, but it also helps regulate gene expression.How is DNA organized in chromatin and chromosomes?every cell in human body contains a full genome, which is every gene in our DNA. each gene isn't switched in in every cell. hair, saliva, etc. can all function as DNA evidence because they all contain our unique genes.What is the significance of genes and the genome in making each person unique? how does this allow investigators to use any type of cell for DNA evidence?They are able to differentiate into a variety of cell types. clinically significant because it can help regenerate tissues for someone who needs repair in the bodyhow do stem cells function and why is that clinically significant?TRANSCRIPTION (transcribe info from DNA -> RNA) 1. transcription factors bind 2. RNA polymerase - an enzyme - binds gene and unwinds DNA, and then makes mRNA from the DNA using base pairs that match. ex. T matches A, C matches G 3. mRNA is edited 4. mRNA leaves nucleus Then, mRNA needs to be translated from nucleic acid "language" to proteins (amino acid "language") 1. ribosome attaches to mRNA. 2. mRNA codon pairs with the complementary anticodon, which leads to one specific amino acid. 3. more amino acids are added. 4. chain of amino acids makes a new protein, releasing from ribosome and then made into a functional 3D structure.describe process of protein synthesis, beginning with DNA in the nucleus to complete protein in the cytoplasm using the terms below.3 nucleotide base sequence on mRNA that corresponds to specific amino acidwhat is a codonRNA polymerase (an enzyme) binds gene and unwinds DNA, then synthesizes mRNA from DNA using complementary base pairs.describe when, where, and how DNA replication occurs using DNA polymerase and complementary base pairs.Interphase (prepping for mitosis) is vast majority of what cell does. G1: function, prep for division S: DNA replication G2: final prep Mitosis Prophase Metaphase Anaphase Telophasedescribe cell cycle including interphase (G1, S, and G2) and mitosisa tumor is just cell division that is out of control.how does a cancerous tumor relate to the cell cycle?oncogenes promote cancer (cell growth). Tumor suppressor genes: inhibit cancer. apoptosis refers to programmed cell death, so we could use that to have cancer cells kill themselves. we could also switch on tumor suppressor genes or switch off oncogeneswhat are the roles of genes in cancer, specifically oncogenes and tumor suppressor genes? how can this help us find cancer cures?no. there are racial ethnic and class-based disparities. some of these are related to diet, exercise, smoking, and other lifestyle factors that are shaped by money, access to healthy food, and education or culture. even the culture of going to the doctor when you're sick or not going can affect cancer rates. this impacts how we address cancer because we need to have an awareness of differences in populationsare all people affected equally by cancer? what does term "cancer disparities" mean and how does this impact how we address cancer?division of the cell's nucleus into 2 equal nuclei. Cell division of one cell consists of mitosis and cytokinesis to produce two identical cells.describe goal of mitosis. when is it used?prophase: 2 chromatids are joined at centromere, spindle forms. metaphase: chromosomes line up at metaphase plate. anaphase: 2 sister chromatids separate into daughter chromosomes. telophase: Chromosomes uncoil. Nucleus reappearsbriefly discuss prophase, metaphase, anaphase and telophase.Cytokinesis occurs after mitosis. consists of splitting cytoplasm by cleavage furrowhow does cytokinesis relate to mitosis?Division of cells that produces gametes (ova and sperm) with half the number of chromosomes (23).describe goal of meiosis and why it is important for reproduction.meiosis is cells divide to form ova and sperm that have 1/2 of the chromosomes an embryo will need. 23 plus 23 = 46. mitosis is the division of regular cells that all contain 46 chromosomones. original cell divides into two.compare meiosis to mitosismeoisis I replicates DNA from 46 to 23 chromosomes: homologous pairs of chromosomes crossover, line up randomly, split, and then cytoplasm divides into 2 cells. each haploid has 23 chromosomes. meoisis II is same thing but with no DNA replication. it divides sister chromatids.briefly describe meiosis I and II, including homologous chromosomes and diploid (46 chromosomes) vs haploid (23 chromosomes) cellsmeoisis produces variation is genes, through recombining genes in random lineup of genes in meiosis I. then when you combine a unique ova with a unique sperm you get 1 in 64 trillion unique genomeshow does genetic recombination (random lineup and crossing over in meiosis I) create unique gametes?all chemical reactions in the bodywhat is metabolism?1st law of thermodynamics says that energy can't be created nor destroyed, it only can change form. 2nd law says when we convert energy to a different form, some of it becomes unavailable to do work. when we eat food, it gets turned into ATP through an exergonic (energy releasing) reaction. this is part 1 of the coupled reaction; part 2 is when the cell uses the ATP in order to do work. The second part is endergonic (requires energy). All of this is part of bioenergetics, or the flow of energy in living organisms.describe process of eating food and converting it to ATP to be used by cells using terms: bioenergetics, 1st and 2nd laws of thermodynamics, endergonic vs exergonic reactions, coupled reactions, and ATP.crash course. 1. glycolysis 2. citric acid cycle 3. electron transportdescribe metabolism using anabolic and endergonic vs. catabolic and exergonic reactions. how are carbs you eat broken down to produce energy in form of ATP? for each step, explain where step occurs, what molecules go IN to each step, and what molecules come OUT of each step. is the step aerobic or anaerobic?arsenic in the water, cyanide, diabeteswhat factors can disrupt cell respiration?1. glycolysis: exergonic reaction that converts glucose + NAD + ADP + Pi -> 2 piruvic acid + NADH + 2 ATP 2. glycogenesis: formation of glycogen from glucose glycogenolysis: conversion back to glucose 3. lipogenesis: formation of fat after blood glucose is elevated post-mealdescribe how glucose can be used to make? 1. ATP via cell respiration in glycolysis 2. glycogen via glycogenesis and then converted back via glycogenolysis 3. fats via lipogenesiswhen fat stored in adipose tissue is going to be utilized as energy, lipase enzymes hydrolyze triglycerides into glycerol and free fatty acids these molecules (mostly the fatty acids) act as blood-borne energy carriers and can be used by liver, skeletal muscle and other organs for cell respirationdescribe lipolysis: the breakdown of fats (triglyercides) into glycerol and fatty acids.1. betaoxidation -> acetyl CoA -> citric acid cycle / electron transport = ATP 2. betaoxidation -> acetyl CoA -> ketone bodies (ketogenesis)describe breakdown of fatty acids using beta oxidation20 amino acids are needed to build proteins for growth or to replace proteins that are turned over.describe how proteins are used for amino acids (essential amino acids)1. protein synthesis 2. transamination - one amino acid is converted to form another 3. oxidative deamination (NH3) to make a. urea b. ATP being used in citric acid cycle / electron transport c. glucose (glucogenesis) for cell respiration for ATP d. fat (lipogenesis)describe pathways of amino acidslets some substances pass, but not otherswhat is selective permeability?carrier-mediated transport uses a carrier protein to help a substance get across the membrane, whereas non carrier-mediated transport goes through the membrane on its owncompare carrier-mediated vs. non-carrier-mediated transport (across cell membrane)passive (no energy needed): Going down concentration gradient (ie. diffusion)(high to low) active: energy needed going against concentration gradient (low to high)is energy needed to transport molecules across membrane? compare passive vs. active transport in relation to diffusionhe movement of molecules from an area of high to low concentration (moving down the concentration gradient) think sugar cube dissolving into water. sugar molecules are going from cube (high concentration) to water (low concentration)what is diffusion? why are concentration gradient and permeability the 2 conditions needed? what can and can't diffuse through plasma membrane?diffusion requires a permeable membrane and a concentration gradient that goes from high to low in order to occur quickly.how do concentration gradient, temp., molecule size, & surface area affect diffusion rate?Diffusion of water (solvent) across the membrane; requires selectively permeable membrane and a concentration gradient (difference in concentration of a solute on the 2 sides of a selectively permeable membrane)what is osmosis?Tonicity is used to describe the effect of a solution on the osmotic movement of water. RBCs in isotonic solution such as IV fluid will not gain or lose water. In hypertonic they gain water and in hypotonic they lose itwhat happens in hypotonic, isotonic, and hypertonic solutions? what should you use for IV fluids and why???what is the role of osmotic pressure?Some transport required Protein carriers to transport molecules across the membrane. Two types of carrier mediated transport are facilitated diffusion and active transport (needs energy). Large polar molecules can't pass thru phospholipid bilayer and require carrier proteins in membrane to get there In facilitated diffusion, glucose or another small molecule binds to a carrier protein, which then undergoes a conformation change to release the molecule to other side of the membrane.discuss how carrier-mediated transport allows cells to take up large or polar molecules.GLUT transport carriers for glucose need the pancreas to secrete insulin in order to carry glucose via facilitated diffusion, & without that they can't help a person maintain glucose homeostasishow is GLUT which is specific for glucose, affected in our diabetic patient John?describe active transport using a carrier, i.e. Ca+ and Na+/K+ pumps to do work.