Flashcards
Human Biology Chapter 2
Flashcards do conjunto (44)
- 1CHNOPSCarbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.
The most significant elements found in all organisms. - 2MoleculeWhen two or more atoms bond together
- 3CompoundWhen two or more different elements bond together
- 4IonWhen electrons are transferred from one atom to another. Ionic compounds are held together by an attraction between negatively and positively charged ions called an Ionic bond. (NaCl or table salt) These are weak bonds (salt dissolves in water)
- 5Covalent BondIs the sharing of electrons in such a way that each atom has a complete outer orbital. This normally between two nonmetals. These are strong bonds
- 6Nonpolar Covalent BondWhen the sharing of electrons between two atoms is fairly equal. (H 2, O 2, CH 4)
- 7Polar Covalent BondThe unequal sharing of electrons in a covalent bond. (Water is a polar molecule)
- 8Hydrogen BondingA weak attraction between a slightly positive hydrogen atom and a slightly negative oxygen or nitrogen atom within the same or a different molecule. This bond is weaker than Ionic and Covalent bonding however many of the important properties of water are due to hydrogen bonding. (Hydrogen bonds hold two strands of DNA together)
- 9Properties of Water1. Water has a high heat capacity (can absorb and hold heat energy
2. Water has a high heat of vaporization
3. Water is a solvent
4. Water molecules are cohesive and adhesive
5. Water has a high surface tension
6. Frozen water is less dense than liquid water - 10AcidsSubstances that release hydrogen (H+) when they disassociate in water. Therefore they contain a higher concentration of hydrogen (H+) ions than hydroxide (OH-) ions (lemon juice, tomatoes, vinegar, coffee, hydrochloric acid)
- 11BasesBases are substances that either take up hydrogen ions (H+) or release hydroxide ions (OH-). They contain a higher concentration of OH- than H+. (baking soda, antacids, sodium hydroxide)
- 12pH ScaleUsed to indicate the acidity or basicity (alkalinity) of solutions. A pH scale ranges from 0 to 14. A pH of 7 represents a neutral state in which H+ = OH-. A pH below 7 is an acidic solution because the hydrogen ion concentration is greater than the hydroxide concentration. A pH above 7 is basic because hydroxide ion concentration is granter than hydrogen ion. concentration.
- 13BufferA substance that keeps pH within normal limits.
- 14If blood pH falls below 7.4 (alkaline)Acidosis sets in. Life threatening.
- 15If blood goes above a pH of 7.4 (alkaline)alkalosis sets in. Life threatening.
- 16Organic MoleculesAlways contain Carbon (C) and Hydrogen (H).
- 17MonomerSimple organic molecule that exists individually or can link with other monomers to form:
- 18PolymerForm when monomers link with other monomers.
- 19Monomers -- > PolymersM: Monosaccharide P: Carbohydrate Polysaccharide (Starch, glycogen, cellulose)
M: Fatty Acid P: Lipid
M: Amino Acid P: Protein
M: Nucleotide P: Nucleic Acid - 20Dehydration ReactionA way of joining monomers to build polymers. An OH and an H (the equivalent of a water molecule) are removed as the reaction proceeds.
- 21Hydrolysis ReactionThe components of water are added breaking down a polymer to monomers.
- 22CarbohydratesFunction for quick fuel and short-term energy shortage in all organisms. Class of organic compounds that typically contain carbon, hydrogen, and oxygen in a 1:2:1 ratio; includes the monosaccharides, disaccharides, and polysaccharides. Carbohydrate molecules are characterized by the presence of the atomic grouping H-C-OH.
- 23MonosaccharideIf the number of Carbon atoms in a molecule is low (from 3 to 7) then the Carbohydrate is a simple sugar, or monosaccharide. Pentose is a 5-Carbon sugar and hexose is a 6-Carbon sugar. Glucose is a hexose sugar found in our blood. Glucose, Fructose, Galactose all occur as ring structures with the molecular formula C6 H12 O6
- 24DisaccharideContains two monosaccharides that have joined during a dehydration reaction. (sucrose, lactose)
- 25PolysaccharideLong polymers such as starch, glycogen, and cellulose that contain many glucose subunits. Starch and glycogen are large storage forms of glucose found in plants and animals. Starch has fewer side branches, or chains of glucose that branch off the main chain than does glycogen.
- 26LipidsContain more energy per gram than other biological molecules while fats and oils function as energy storage molecules in organisms. Fats and oils form when one glycerol molecule reacts with three fatty acid molecules (Fig. 2.19). A fat molecule is sometimes called a triglyceride because of its three-part structure, and the term neutral fat is sometimes used because the molecule is non polar. The are insoluble in water. Phospholipids are important structural components of the cell membrane.
Phospholipids, Fats and Oils, Steroids
- 27Fats and OilsFats used for long-term energy storage, insulates against heat loss, forms a protective cushion around major organs, tend to be animal derived, and are solid at room temperature.
Oils tend to be plant derived and are liquid at room temperature.
They form when one glycerol molecule reacts with three fatty acid molecules (triglyceride or neutral fat). - 28Saturated vs Unsaturated Fats vs Trans FatSaturated: No double covalent bonds between carbon atoms (lard and butter)
Unsaturated: Double bonds between carbon atoms wherever the number of hydrogens is less than two per carbon atom (vegetable oils)
Trans: produced by hydrogenation or the chemical addition of hydrogen to vegetable oils (processed foods)
- 29PhospholipidsContain a phosphate group. They are constructed like fats, except that in place of the third fatty acid, there is a polar phosphate group or a grouping that contains both phosphate and nitrogen. The molecule has a polar (hydrophilic) head while the rest of the molecule becomes non polar (hydrophobic).
- 30SteroidsBackbone of four fused carbon rings (cholesterol)
- 31ProteinsPolymers composed of amino acid monomers. An amino acid has a central carbon bonded to a hydrogen atom and three functional groups. The R group determines the uniqueness of each amino acid. Some proteins are enzymes.
- 32EnzymesSpeed chemical reactions, biological catalyst
- 33Enzyme Cycle1. Enzyme and substrate come together at active site of enzyme, forming an enzyme-substrate complex.
2. Enzyme catalyzes reaction and transforms substrate into products.
3. When reaction is complete, enzyme is unchanged and free to catalyze same reaction again on a new substrate. - 346 Major Classes of EnzymesLigase, Lyase, Hydrolase, Transferase, Isomerase, Oxido-reductase, Kinase
- 35PeptideA polypeptide is a single chain of amino acids. A peptide bond joins two amino acids.
- 36Levels of Protein Organization1. Primary Structure is the linear sequence of the amino acids.
2. Secondary Structure occurs when the protein takes on a certain orientation in space (alpha helix, beta sheet)
3. Tertiary Structure is the final three-dimensional shape, due in part to the various bonding between R groups.
4. Quaternary Structure is found in proteins with multiple polypeptide chains. - 37Denaturing of a ProteinWhen proteins are exposed to extreme heat or pH
- 38Nucleic AcidsDNA (deoxyribonucleic acid)
RNA (ribonucleic acid)
Both are polymers of nucleotides and every nucleotide is a molecular complex of Phosphate, Pentose Sugar (Ribose or Deoxyribose), and nitrogen-containing base - 39DNADNA stores genetic information and replicates to transmit its information when a cell divides or organism reproduces. It also contains the instructions for producing RNA.
- 40DNASugar: Deoxyribose
Bases: (A) Adenine, (G) Guanine, (T) Thymine, (C) Cytosine
(T) Thymine always pairs with (A) Adenine, (G) Guanine always pairs with (C) Cytosine
Double stranded helix - 41RNAContains the instructions for producing proteins, which direct most of life's processes.
- 42RNASugar: Ribose
Bases: (A) Adenine, (G) Guanine, (U) Uracil, (C) Cytosine
(A) Adenine always pairs with (U) Uracil, (G) Guanine always pairs with (C) Cytosine
Single stranded
Formed by complementary base pairing with one DNA strand. - 43ATPHigh-Energy molecule that undergoes hydrolysis and energy is released. It is the energy currency of the cell.
- 44NucleotideEach nucleotide of a nucleic acid contains a phosphate group, a pentose sugar, and nitrogen-containing base.
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- Undergraduate Human Biology FlashCards sobre Human Biology Chapter 2, criado por iracema23 em 27-09-2015.
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