BIO200H5 Lecture Notes - Lecture 3: Halocarbon, Nitro Compound, Dissociation Constant

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28 Dec 2014

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Introduction 4: drugs as molecules i - interactions with water and. Lipids solubility: why study the interaction of drug molecules. Usually within the body and exposed to water The problem: the sites of specific drug action: exposed to water (proteins, nucleic acids, drug must be water soluble to reach them. But the body barriers to cross are biological membranes: they are lipoid. Drugs must also be lipid soluble to reach them if taken by mouth. The ideal drug: will have both water and lipid solubility. What makes molecules water soluble: water is a polar solvent. Polar groups necessary: examples of groups that tend to increase polarity: Cooh -oh -nh2 -c=o: what makes drugs lipid soluble, lipids are non-polar solvents. Non-polar groups necessary: examples of groups that tend to decrease polarity: I -br -cl -ch2 or ch3 -f (aromatic parent compound) Recap: drugs have polar and non polar groups. Pm/b = pm/b (methane) x (pch3)3 x pbranch x poh.

Related Questions

1. Use the following definitions and phrases to describe to which molecules of life and their subunits it belongs:

a. Energy-storing molecule, typically water soluble - b. Subunits are called monosaccharides â c. Used to speed chemical reactions - d. Subunits are joined to each other with peptide bonds - e. Most prevalent molecule in cell membranes - f. Some of them function as hormones - g. Used for storing, transmitting, and executing genetic information - h. Subunits are nucleotides

2. Weak hydrogen bonds between water molecules are responsible for the many properties of water. Acidity is expressed as pH. Buffers stabilize pH. a. What characteristics of water molecule makes it polar? Provide two examples why this property is important in microbiology. b. What is the role of buffers in living organisms, including microbes? c. What must be added to pure water to decrease OH- and/or H+ concentration, respectively

3. Carbohydrates serve as storage molecules and structural material. Lipids are hydrophobic molecules; phospholipids are main component of cell membranes. Protein has a complex structure based on identity and sequence of amino acids. Nucleic acids (DNA and RNA) are genetic station of storage information and for synthesis of proteins. ATP serve as the main energy source in the living cell. a. Name the subunits (building blocks) of carbs, simple lipids, proteins, and nucleic acids b. What level of protein structure is described as an alpha helix? c. If DNA is placed in boiling water, what and how the molecule would change?

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.

Lysosomes

Endosomes

Peroxisomes

Nucleosomes

Biologists cannot possibly study all living species. Instead, they try to understand cell behavior by studying a select subset of them. Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies?

rapid rate of reproduction

all of the above

ability to grow under controlled conditions

amenability to genetic manipulation

By definition, prokaryotic cells do not possess __________.

ribosomes.

a nucleus.

membrane bilayers.

replication machinery.

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a microscope is limited by the __________ of light.

intensity

absorption

wavelength

filtering

Choose the phrase that best completes this sentence: Microtubules ____________ and are required to pull duplicated chromosomes to opposite poles of dividing cells.

generate contractile forces

can rapidly reorganize

are found in especially large numbers in muscle cells

are intermediate in thickness

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton?

cell division

cell motility

vesicle transport

membrane support

DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA?

It contains thymine.

It has 5'-to-3' directionality.

It is single-stranded.

It contains uracil.

Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they ____________________.

prevent additional bonds from being formed with the bonded atoms.

limit the rotation of the bonded atoms.

create a new arrangement of electron shells.

change the reactivity of the bonded atoms.

Drosophila melanogaster is a/an __________. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model.

mammal

amphibian

bird

insect

10.

If the isotope 32S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons will the isotope 35S have, respectively?

16, 19, 17

16, 19, 15

16, 19, 16

16, 20, 15

11.

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?

cell

organelle

protein

DNA

12.

Macromolecules in the cell can often interact transiently as a result of noncovalent interactions. These weak interactions also produce stable, highly specific interactions between molecules. Which of the factors below is the most significant in determining whether the interaction will be transient or stable?

the concentration of each molecule

the size of each molecule

surface complementarity between molecules

the rate of synthesis

13.

Many of the mechanisms that cells use for maintenance and reproduction were first studied at the molecular level in bacteria. Which bacterial species had a central role in advancing the field of molecular biology?

E. coli

S. pombe

C. elegans

D. melanogaster

14.

Many types of cells have stores of lipids in their cytoplasm, usually seen as fat droplets. What is the lipid most commonly found in these droplets?

cholesterol

isoprene

triacylglycerol

palmitic acid

15.

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are __________________.

anaerobes.

viruses.

parasites.

endosymbionts.

16.

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of material âburnedâ and the form of energy produced during cellular respiration?

17.

Polar covalent bonds are formed when the electrons in the bond are not shared equally between the two nuclei. Which one of these molecules contains polar bonds?

For Discussion (2-3 paragraphs) â¢ What was the concentration of your pre-diluted NPs? â¢ Determine the effect of NPs on brine shrimp lethality. â¢ Determine the effect of NPs on cell viability. â¢ What is (are) the control(s) in this experiment? What is its purpose? â¢ Based on your data in this lab, what is a safe concentration for brine shrimp Threshold Level of Toxicity (TTL)? â¢ Often indicator species are used to study the overall health of an ecosystem. If you were to study an ecosystem containing brine shrimp, would you use it as an indicator species? Why or Why not? Explain your reasoning. â¢ What possible sources of error were present in this experiment?

Introduction

LD50 is a commonly used term to describe acute toxicity: LD stands for Lethal Dose and 50 is used because the dose could kill 50% of the animals exposed to the chemical. For LD50 tests, the animals are given specific amounts of the chemical, orally, by injection or dermally. The value is then reported along with the method of administration and the type of animal used in the test. LD50 is typically reported in milligrams or grams per kilogram of body weight of the animal. The lower the LD50 is, the higher the toxicity of the chemical would be. This information is always provided in Safety Data Sheet (SDS) of chemicals in the âtoxicity dataâ category. A similar measure, the LC50 is usually used to describe the ecological hazards of chemicals. LC stands for lethal concentration that could kill 50% of the animals after 24-96 hours. This value is always provided in Safety Data Sheet (SDS) of chemicals in the âEcological Dataâ category. In this lab, you will be measuring LC50 or LD50 of iron oxide nanoparticles using brine shrimp. Iron oxide nanoparticles are magnetic. Application of magnetic nanoparticles ranges from magnetic storage media to medical industry where they can be used for targeted drug delivery or as contrast agents in MRI. Thus, measuring environmental and biological toxicity of these nanoparticles is crucial. To test toxicity of any such reagents on small organisms, Daphnia and brine shrimps (also known as Artemia) can be used. Artimia are found in salt lakes around the world. They are important live food for aquarium fish. In this lab, you will use brine shrimp to measure toxicity of the nanoparticles. Trypan blue is a stain used to assess cell viability. It is able to diffuse through cell membranes of dead cells but is unable to permeate live cells. This stain can be used to assess cell survival 1 Fall 2017 following exposure to chemicals, nanoparticles and experimental drugs. The ratio of live: dead cells can be used as a preliminary assessment of cytotoxicity and translated to tissue viability.

Methods Part A: Serial Dilution of NP Solution 1) Label 5 test tubes as 0, 1:1, 1:10, 1:100, 1:1000 2) Add 2mL of seawater to tube 0 3) Add 2mL of specific group stock solution to tube 1:1 and add 2mL of seawater to it. 4) Transfer 1mL of stock solution to tube 1:10 and add 9mL of seawater to this tube 5) Transfer 1mL of 1:10 solution to the tube labeled as 1:100 and add 9mL of seawater to â¨this tube 6) Transfer 1mL of 1:100 solution to the test tube labeled as 1:1000 and add 9mL of â¨seawater to this tube Part B: Preparation of test environments 1) Label 5 wells of 6-well plate as control (0), 1:1, 1:10, 1:100 and 1:1000 2) Label 3 petri dishes as: control (0), 1:1 and 1:1000 â¨NOTE: Be sure to include your initials on all plates 3) Transfer 2mL of each solution from the corresponding test tube to the respective wells on your six-well plate and each petri dish Part C: Preparing specimens for the Trypan blue cell viability test 1) Transfer 2 brine shrimp into each of the pre-labeled petri dishes containing the solution of NPs and seawater (0, 1:1 & 1:1000) and set a timer for 30 minutes. 2) Transfer a single brine shrimp into the unlabeled petri dish with a drop (~50ul) of seawater and use the dissecting microscope to make observations related to the behavior and morphology of untreated brine shrimp.â¨Make observations in lab notebook of all samples Part D: Preparation of specimens for the toxicity assay 1) 2) 3) 4) 5) Add 10 brine shrimp into each well in the 6 -well plate Make observations in lab notebook Using a dissecting microscope (if needed), count the number of brine shrimp in each well (alive shrimps).â¨Record your data in your notebook using the graphic below as a template. Close the plate and store it for next observation.â¨Observations must be done within 24h-96hâ¨Note: There will be times allocated and a sign up paper for observations Part E: Trypan blue viability test 2 Fall 2017 1) Label 3 glass slides to match the petri dishes prepared in Part C. 2) Transfer 1 brine shrimp from each petri dish onto the corresponding slide. â¨Make observations in your lab notebook 3) Add a drop (~60 Î¼l) of PBS on top of each specimen 4) Add 60 Î¼l of Trypan blue to your shrimp and incubate for 1-2 minutes at room â¨temperature. 5) Wick away excess liquid 6) Add 100 Î¼l PBS to sample and observe (while alive!), looking for blue cells, using the â¨dissecting scope â¨Make observations in your lab notebook 7) Label 3 microfuge tubes to align with each sample. 8) Transfer each brine shrimp from the slide into the corresponding microfuge tube 9) Add 50 Î¼l of PBS to the tube and use the mechanical disruption tool to homogenize the â¨sample for ~2 minutes until a cell suspension has been generated. 10) Load 30-50 Î¼l of your sample onto a new glass slide and add a cover slip. 11)Observe the sample on high power and use the scale below to qualitatively assess cytotoxicityâ 0-no blue 1-some blue 2-fairly blue 3-totally blue.

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BIO200H5 Lecture Notes - Lecture 3: Halocarbon, Nitro Compound, Dissociation Constant

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