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86 Cards in this Set
- Front
- Back
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What are living creatures?
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chemical systems
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What laws do living organisms obey?
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physical and chemical laws
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The chemistry of life is what?
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1. organic chemistry
2. enormously complex 3. dominated and coordinated by collections of plymeric molecules 4. tightly regulated |
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What do you need to understand first to understand how cells work?
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cells chemistry
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What does an atom contain?
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1. nucleus
2. cloud of orbiting electrons |
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What unit is atomic and molecular weights specified as?
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Daltons
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Most proteins have a moleular weight of more than ____ kilodaltons.
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10,000
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Atomic weight
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number of electrons+number of protons
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Atomic number
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half of atomic weight
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What is the most widely used meausre in chemistry?
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moles
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What are moles?
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number of molecules available in chemical reactions.
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What elements (by number of atoms) in the human body is greater than that of the earth's crust?
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H, C, N,
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What does the atmosphere contain?
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79.09% N
20.95% O .93% Ar 0.039% Co2 |
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Life is mainly composed of what elements?
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Light elements
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What are the 99% of the total atoms in human body?
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C, N, O, H
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What are the 0.9% of the total atoms in human body?
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Na, Mg, K, Ca, P, S, Cl
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What are essential trace elements?
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V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Se, I, F
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What are unknown if they are needed?
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Ni, B, Si
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What news about bacterium made headlines in several news?
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bacterium that can grwo by using Arsenic instead of phosphorus
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What atoms have chemical reactivity (tendency to form bonds with other atoms) ?
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H,C, N, O, Na, Mg, P, S, Cl, K, Ca
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Which atoms will form bonds?
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Atoms with unfilled outer shells
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What bond is the sharing of electrons?
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covalent bond
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What bond is the transfer of electrons?
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ionic bond
(atom that gains electrons is negative ion) |
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What is unique about covalent bonds?
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1.they have a characteristic bond length
-to close:repel -to far: no attraction ex. hydrogen bond lenght is .074 2. Characterized by particular geometries |
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Covalent and noncovalent bonds vary in____ and ____
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length and strength
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Bonds length
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covalent: .15 nm
Non covlent -ionic: .25nm -hydrogen .30nm -VderW .35 |
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Bond strenght (kcal/mole)
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Covalent: 90
Noncovalent: - ionic 80 3(water) -hydrogen 4 1 -VderW .1 .1 |
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In what bond are atoms free to rotate around?
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a single bond
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Def of single bond
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one shared electrons between two atoms
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def of double bond
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two shared electrons between two atoms
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Characteristic of double bonds?
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planer, shorter, and more riged
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____ and ____ influences the shape of many macromolecules
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bond geometry
bond felexibility |
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Def of polar covalent bonds
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-electrons are shared unequally
ex. water |
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What do polar covalent bonds in large molecules create?
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They create surface regions of partial postive or negative charges.
-these are called complemetnary charged surfaces |
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what do complementary charged surfaces allow larger molecules to do?
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bind to each other
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Def. Hydrogen bonds
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bond which froms when hyrgoen in a polar covalet likage comes close to a negtively charged atom (O, N)
ex. water molecules held together to make water |
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What molecules form acids and bases in water?
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polar molecules
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What is an acid?
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substance sthat release protons
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What molecules continously exchange protons?
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water
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At neutral pH there are equal numbers of __ and __ ions (each at 10^-7 M) Why?
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hyrdonium ion (H3O+)
hydroxyl ion (OH-) because protons moves form one molecule to the other |
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Amino
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NH2
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Carbonyl
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C=O
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carboxyl
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COOH
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hydroxyl
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OH
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methyl
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CH3
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phosphoryl
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PO3^2-
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Cells are formed from?
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carbon compounds
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Chemical composition of a bacterial cell from greatest number of types of each molecule
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macromolecules > other small molecules > sugars > nucleotides + amino acids > fatty acids > ionorganic ions > water
macromolecules=proteins, nucleic acids, polysaccharides and phospholipids |
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Chemical composition of a bacterial cell from greatest percentage of total cell weight?
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water > macromolecules > inorganic ions + sugars + fatty acids > amino acids + nuclotides> other small molecules
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How many different kinds of carbon compounds are in a soluiton?
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1000 different kinds
MW= 100-1000 D (<30 carbon atoms) |
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What are small organic molecules used for?
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-as monomer subunits to contruct large plymeric macromolecules
-broken dwon and used as energy sources -transformed inot different small molecules in metabolic pathways |
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Most of the cell's mass consist of these four families of molecules and the larger structures taht are made by linking them together
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Building blocks of cells
sugars fathy acids amino acids nucleotides |
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sugars link to form
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polysacchrides
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fatty acids link to form
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fats, lipids, membranes
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amino acids link to form
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proteins
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nucleotides link to form
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nucleic acids
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What 2 things is a cell composed of
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Chemicals (macromolecules) 30%
Water 70% |
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What are the macromolecules that compose 30% of the cell (from greatest)
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proteins>RNA>ions, small molecules>polysaccharides+phospholipids>DNA
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Molecules with the formula CnH(2n)On are called?
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Sugars
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Monosaccharides can be covalently linked to make ___,___,___.
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disaccharides, oligosaccharides, and giant polysaccharies.
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How can branched chains form in sugars?
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The can form because there are several reactive hydroxy (OH) groups on each sugar
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Hydrolysis
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water consumed
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Condensation
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water expelled
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Fatty acids are componenets of what part of the cell?
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cell membranes
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Fatty acids are composed of a ____ head and a ____ tail
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hydrophilic ccarboxylic acid head
hydrophobic hydrocarbon tail |
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How are fats stored as?
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As triacylglycerol molecules
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Def of unsaturated fats
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have one or more dobule bonds in their fatty acid chians which produce kins that prevent tight packing
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A phospholipid moleule is composed of ____ _____ tails and a ____ head composed of ___,____,___
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2 hydrophobic fatty acid tails
hydrophilic head: polar group, phosphate, glycerol |
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Amino acids chemical variety comes form what?
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the side chain (R)
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How many standard amino acides are their that vary in thier side chain?
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20
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What happends to amino acids at a pH of 7
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amino acids are ionized
N on amino group becomes postive O on carboxyl group becomes negative |
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What are amino acids composed of?
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amino group: H2N
Hydrogen Carboxyl group: COOH Side chain all attached to a carbon |
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What bond links amino acids together to make protein
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peptide bond
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What can nuclotides act as for a short term?
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short therm carries of chemical energy
by releasing water can form ATP by adding water can from ADP +Pi |
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What are nucleotides composed of?
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triphosphate: PO3-
Sugar Base |
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Ribose surgar vs Deoxyiribose sugar
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OH OH
OH H |
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Macromolecules (proteins, DNA, RNA) are made by adding subunits only to ___ __ of growin chain (in a sequence) via ___ reaction.
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one end
condensation reaction |
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What specify the precise shape of a macromolecue?
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noncovalent bonds
aka to fold into 3-D shape |
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Types of noncovalent interactions
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1. electrostatic attaractions (weak in water)
2. hydrogen bonds 3. van der Waals attraction 4. hydrophobic interaction |
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What are van der Waals attractions
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a type of electrical attraction caused by fluctuating electric charges that arise when 2 atoms come close to each other.
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Noncovalent bonds mediate ___ betwen____
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interactions betwen macromolecules.
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What self assemble by noncovalent interactions of macromolecules
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molecular machines
------>covalent----------> noncovalent subunits--->macromoleulces--> macromolecular complex amino acids--->proteins---> ribosome |
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Debate over defintion of macromolecules ended by
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Theodor Svedberg in 1925
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Theodor Svedberg desgined an____ and perfomred the first studies showin that ___ is a macromolecule with ___ discrete size and shape.
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ultracentrifuge
hemoglobin one |
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Svedberg used____ and ____parameters to demonstrate that the hemoglobin behaved like a ____macromolecule
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theromodynamic
kinetic single |
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Ultracentrifuge are still used today to determine ____ of proteins and other particles, but ____ ____ is the preferred method.
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size
band sedimentation |
