BCHM notes 86563 - NUTR 2030 - 001
Popular in Introduction to Principles of Human Nutrition
86563 - NUTR 2030 - 001
verified elite notetaker
Popular in Nutrition and Food Sciences
verified elite notetaker
This 5 page Class Notes was uploaded by Lyndon Neil on Wednesday January 13, 2016. The Class Notes belongs to 86563 - NUTR 2030 - 001 at Clemson University taught by Deborah Ann Hutcheon in Fall 2015. Since its upload, it has received 57 views. For similar materials see Introduction to Principles of Human Nutrition in Nutrition and Food Sciences at Clemson University.
Reviews for BCHM notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/13/16
BCHM 3050 EXAM 1 NOTES Online Lecture 1: Water, Chapter 3 Water is a universal language 70-80% of world is in water (oceans, rivers, lakes) Our body is 70-80% water Almost everything dissolves in water Two hydrogens and one oxygen o Larger oxygen atom = partial negative charge o Hydrogen atoms have partial positive charges 104.5 degree angle CHEMICAL BONDS: Bonds are formed between two atoms Ionic – very different e- values Covalent – very similar e-values o Nonmetals o Nonpolar covalent: values are very close, electrons are equally shared o Polar covalent: different values (polar means its drawn closer to one) Oxygen and hydrogen in water is POLAR COVALENT DIPOLE: partial positive and partial negative charges are separate, in water the electrons will be drawn to the oxygen Electronegativity values – how strong the attraction is for electrons to go to that atom Extreme left have low electronegativity Extreme right have high electronegativity NONCOVALENT BONDING.. Weakest – Strongest : Dispersion fores, dipole-dipole attraction, hydrogen bonds, ionic interactions Most important noncovalent bonds are: -Hydrogen bonds: Forms between two different water molecules Partial positive hydrogen is attracted to partial negative oxygen of another H20 -Ionic (electrostatic) interactions: two elements with extreme different e- values, so that they can lose/gain electrons (NaCl) Water is ideal biological solvent -it can dissolve ionic and polar substances -shells of water molecules form around ions forming solvation spheres Cohesion: DEW DROPS Ability of water to stick together Hydrogen bonding between water molecules Adhesion: Water sticking to other substances Allows water to stay on spider web Surface tension: Quality of water to be tense at the surface Molecules at the surface aren’t forming H bonds with any molecules above them -Density of water- In its solid form, water is lighter than liquid water The maximum number of hydrogen bonds have formed when water has frozen into ice (ICE FLOATS ON WATER, less dense) Water has a very high melting point (0) and boiling point (100) (due to hydrogen bonding) - Each water molecule can form four hydrogen bonds with other water molecules - Adding solutes to water increases the boiling point, because you have to break those as well - Adding solutes to water lowers the freezing point. Mixing water with something fruity, will take a lower temperature to freeze. Osmotic pressure: Osmosis is the spontaneous passage of solvent molecules through a semipermeable membrane Osmotic pressure is the pressure required to stop the net flow of water across a membrane Osmotic pressure depends on solute concentration - Can be measured with an osmometer or calculated (=iMRT) - Cells may gain or lose water because of the environmental solute concentration - Solute concentration differences between the cell and the environment have important consequences Isotonic solution – concentration is same inside and outside, water comes in and out at the same rate Hypotonic solution – cell exposed to this, solution does not have as much solute, more solute inside the cell than the solution, the solution has more water than solute, so water will go into cell! CELL BURSTING Hypertonic solution – cell exposed to this, solution has too much solute, not enough water, cell has more water than solute, so water leaves, CELL SHRINKING pH, Acids and Bases: - Water can occasionally ionize, forming a hydrogen ion (H+) and a hydroxide ion (OH-) - The ion product of water is Kw = [H+][OH-] - Kw at 25 Celsius and 1 atm is 1.0*10^-14 ACIDS DONATE PROTONS - Strong acids completely dissociate in water - Weak acids do NOT completely dissociate in water BASES ACCEPT PROTONS pH is the measure of the hydrogen ion concentration pH = -log[H+] pH + pOH = 14 pKa is used to express the strength of a weak acid - lower pKa = stronger acid - pKa = -logKa - Ka is the acid dissociation constant Online Lecture 2: Amino Acids, Chapter 5a Amino acids are the building blocks of peptides and proteins Central dogma of cell biology (DNA – RNA – Protein – Traits) Translation: the process of translating an RNA sequence into the corresponding sequence of amino acids to form a protein Proteins are the first biological step towards the outward display of phenotypic traits - They exhibit lots of shapes, structures and functions: Enzymes (enzyme components) Structural Hormones Regulatory Toxins Storage There are 20 standard amino acids (that occur in proteins) Each has an amino (NH3) and carboxyl (COOH) group joined via a –CH- group… The “R” group is the unique feature for each amino acid. - At a very low pH, the amino group has a positive charge - At a very high pH, the carboxyl group has a negative charge - At a neutral pH, they have both positive and negative Characteristics of Amino Acids Amphoteric: they can act as an acid or a base (depending on the pH) Both the COOH and NH3 groups have dissociable proteins Amino acids are “zwitterions”, meaning they can carry + and – charges on the same molecule (normally in equal numbers, so no net charge) The pH when there is no net charge is the “isoelectric point” The middle carbon of amino acids is ASYMMETRIC, meaning that all four attached groups are different. Classification of Amino Acids Based primarily on “R” group properties Potential interactions with water Presence/ absence of dissociable groups Four main groups of amino acids Neutral non-polar (no charge, hydrophobic) Neutral polar (no charge, hydrophilic) Acidic (extra carboxyl; can be – charged), the carboxyl group is acidic and wants to give away Hs Basic (extra amino; can be + charged), the amino group is basic and wants to keep Hs TITRATION: - You start out at a very low pH and you’re dumping base into it - As the pH increases, you will see different properties of the amino acid - Pk1 and pk2 - COOH will let go of protons first - Pk1 is the pH when 50% of carboxyl group have let go of protons and become COO-, ratio of conjugate base over weak acid = 1 (50%) ([A-]/[HA]) - BEFORE pk1, amino has a positive charge (+1) - Pk2 is the pH when 50% of the amino group exists as NH3+, and the other 50% has been converted into NH2, so NH3+ has let go of protons - AFTER PK2, amino has a negative charge (-1) - Beyond pk2, the amino group is converted to NH2 - IN BETWEEN PK1 and PK2, amino has a neutral charge (0) - Pi value is value where 100% of amino exists as a charge of zero. - Essentially an average of PK1 and PK2 Essential vs. Non-essential amino acids -essential must be obtained from diet (from foods) -Non-essential can be made by the human body (biosynthesis) Amino acids can link together to form short peptides or long peptides - Glutathione is a tripeptide (3) found in most all organisms and is involved in protein and DNA synthesis, toxic substance metabolism, and amino acid transport (Glu-Cys-Gly) - Vasopressin is an antidiuretic hormone that regulates water balance, appetite, and body temperature - Oxytocin is a peptide that aids in uterine contraction and lactation Online Lecture 3: Proteins, Chapter 5b Proteins are super complex LEVELS: primary, secondary, tertiary, and quaternary i=1 m= (moles/.03L) r= .0821 t= 298 .01=x(.0821)(298) 24.4658 .0004087= moles/.03 moles= .000012262x = .056
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'