Topic 1 - Biological Molecules Flashcards
What is common ancestry?
All life shares a common genetic origin.
Define monomers.
Small units forming larger biological molecules.
What are polymers?
Large molecules made of many monomers.
What are dimers?
Molecules formed from two joined monomers.
What are condensation reactions?
Join monomers, releasing water to form bonds.
What are hydrolysis reactions?
Split polymers into monomers using water.
What are carbohydrates?
Molecules containing carbon, hydrogen, and oxygen.
Define monosaccharides.
Simplest carbohydrates; basic units of larger carbs.
Name some important monosaccharides.
- Glucose
- Fructose
- Galactose
What are glucose isomers?
- α-glucose
- β-glucose
Define disaccharides.
Two monosaccharides linked by glycosidic bonds.
What are glycosidic bonds?
Covalent bonds formed between carbohydrate molecules.
What is maltose?
Disaccharide of two glucose molecules.
What is sucrose?
Disaccharide of glucose and fructose.
What is lactose?
Disaccharide of glucose and galactose.
Define reducing sugars.
Monosaccharides and some disaccharides that reduce.
What is Benedict’s test?
Test for reducing sugars using reagent and heat.
What indicates a positive result in Benedict’s test?
Brick red precipitate indicates reducing sugar presence.
What indicates a negative result in Benedict’s test?
Remains blue if no reducing sugar is present.
Define non-reducing sugars.
Disaccharides that do not reduce, like sucrose.
What are calibration curves?
Graphs plotting glucose concentration against absorbance.
Define polysaccharides.
Long chains of monosaccharides linked by condensation.
What is starch?
Polysaccharide made of α-glucose in helical form.
What stabilizes starch structure?
Hydrogen bonds between hydroxyl groups.
What is serial dilution?
Stepwise dilution to determine unknown concentrations.
What is the iodine test?
Test for starch using iodine solution.
What indicates a positive starch result?
Blue/black color indicates presence of starch.
What indicates a negative starch result?
Orange color indicates absence of starch.
What is glycogen?
Branched polysaccharide for quick glucose release.
What are 1-6 glycosidic bonds?
Bonds that create branching in glycogen.
Describe starch structure.
Insoluble, large, helical, and compact for storage.
What allows rapid glucose conversion in glycogen?
Branched structure allows rapid glucose conversion.
What is cellulose composition?
Polysaccharide made of β-glucose molecules.
What are glycosidic bonds in cellulose?
Bonds between carbon 1 and 4 via condensation.
How is cellulose oriented?
Every other glucose flipped 180 degrees.
What are microfibrils?
Strong structures formed by hydrogen bonding in cellulose.
What is turgor pressure?
Pressure from water in plant cells.
Define lipids.
Fats and oils made of carbon, hydrogen, oxygen.
What are triglycerides?
Three fatty acids linked to one glycerol.
What are ester bonds?
Bonds formed during triglyceride synthesis.
What are the types of fatty acids?
- Unsaturated contains double bonds
- Saturated does not
What are phospholipids?
Two fatty acids and one phosphate group.
What is the hydrophilic head?
Phosphate group that interacts with water.
What are hydrophobic tails?
Fatty acids that repel water.
What is the phospholipid bilayer?
Cell membrane structure with hydrophobic interactions.
What is the lipid test?
Dissolve in ethanol, then add water.
What indicates a positive lipid result?
White emulsion indicates presence of lipids.
Define proteins.
Polymers made of amino acid monomers.
What are amino acids?
Building blocks of proteins containing C, H, O, N.
What are peptide bonds?
Bonds formed between amino acids in proteins.
What is a dipeptide?
Chain of two amino acids.
What is a polypeptide?
Chain of several hundred amino acids.
What are R groups?
Variable groups in amino acids determining protein diversity.
What is the primary structure of a protein?
Sequence of amino acids in a protein.
What is the secondary structure of a protein?
Folding due to hydrogen bonds in peptide bonds.
What is the tertiary structure of a protein?
Folding due to R group chemical bonds.
What is the quaternary structure of a protein?
Multiple polypeptide chains bonded together.
Define fibrous proteins.
Insoluble proteins with structural roles.
Define globular proteins.
Soluble proteins with unique shapes.
What is keratin?
Fibrous protein in hair, strong and insoluble.
What is collagen?
Fibrous protein in skin, provides strength.
What is the biuret reagent?
Test for proteins using sodium hydroxide and copper sulfate.
What indicates a positive biuret test?
Lilac color indicates presence of proteins.
What indicates a negative biuret test?
Remains blue indicates absence of proteins.
What is chromatography?
Method for separating molecules based on solubility.
Define Rf value.
Ratio of distance moved by sample to solvent.
What is two-dimensional chromatography?
Technique to improve separation by using two solvents.
What are enzymes?
Proteins that act as biological catalysts.
What is activation energy?
Energy required to initiate a chemical reaction.
What does the lock and key model explain?
Specific enzyme-substrate interactions.
What is the active site?
Region of enzyme where substrate binds.
Define substrate.
Molecule that an enzyme acts upon.
What is a catalyst?
Substance that speeds up a reaction without being consumed.
What is enzyme specificity?
Each enzyme catalyzes only one type of reaction.
What are hydrophobic R groups?
Amino acid side chains that repel water.
What are hydrophilic R groups?
Amino acid side chains that attract water.
What is the induced fit model?
Enzyme shape changes to fit substrate upon binding.
What is the enzyme-substrate complex?
Temporary structure formed when substrate binds to enzyme.
What are optimum conditions for enzymes?
Ideal environmental factors for maximum enzyme activity.
How does temperature affect enzyme activity?
Higher temperatures increase kinetic energy and reaction rate.
Define kinetic energy.
Energy of motion affecting molecular movement and interactions.
What is denaturation?
Loss of protein structure due to extreme conditions.
How does pH affect enzyme activity?
Extreme pH disrupts ionic bonds, altering enzyme shape.
What is substrate concentration?
Amount of substrate available for enzyme binding.
Define limiting factor.
Component that restricts the rate of a reaction.
What is enzyme concentration?
Amount of enzyme available to catalyze reactions.
What is competitive inhibition?
Inhibitor resembles substrate, blocking active site access.
What is non-competitive inhibition?
Inhibitor binds elsewhere, altering enzyme function.
What is the reaction rate?
Speed at which reactants are converted to products.
What is enzyme activity?
Measure of how effectively an enzyme catalyzes reactions.
What is substrate binding?
Process of substrate attaching to an enzyme’s active site.
What is product release?
Process where formed product detaches from enzyme.
What is enzyme saturation?
Condition where all active sites are occupied by substrates.
What is reaction equilibrium?
State where reactants and products are formed at equal rates.
What is enzyme regulation?
Mechanisms controlling enzyme activity and reaction rates.
What is DNA?
Polymer of nucleotides carrying genetic information.
What is a DNA nucleotide?
Building block of DNA with three components.
What is deoxyribose?
Sugar component of DNA nucleotides.
What is the phosphate group in nucleotides?
Part of nucleotide linking sugar and backbone.
What is a nitrogenous base?
Organic base in nucleotides, includes adenine.
Name one of the four nitrogenous bases in DNA.
- Adenine
- Thymine
- Cytosine
- Guanine
What are covalent bonds in DNA?
Strong bond linking sugar and phosphate in DNA.
What is the sugar-phosphate backbone?
Structural framework of DNA formed by nucleotides.
What holds complementary bases together in DNA?
Hydrogen bonds.
What are anti-parallel strands in DNA?
Strands running in opposite directions in DNA.
What is the 5’ to 3’ direction?
Direction of DNA strand synthesis by polymerase.
What is DNA helicase?
Enzyme unwinding DNA helix during replication.
What is DNA polymerase?
Enzyme forming phosphodiester bonds in DNA.
What is semi-conservative replication?
Each DNA molecule has one old and one new strand.
What did the Meselson and Stahl experiment demonstrate?
Semi-conservative nature of DNA replication.
What is RNA?
Shorter polymer of nucleotides for genetic transfer.
What is ribose?
Sugar component of RNA nucleotides.
What is uracil?
Base in RNA replacing thymine from DNA.
What are ribosomes?
Cell structures made of RNA and proteins.
What is ATP?
Energy currency of the cell, composed of ribose.
What occurs during ATP hydrolysis?
Reaction releasing energy by breaking phosphate bond.
What is ADP?
Product of ATP hydrolysis, adenosine diphosphate.
What is inorganic phosphate (Pi)?
Released during ATP hydrolysis, used in energy transfer.
What is ATP synthase?
Enzyme catalyzing ATP synthesis from ADP.
What is the hydrolysis reaction?
Reaction releasing energy from ATP.
What is a condensation reaction?
Reaction forming ATP from ADP and Pi.
What is muscle contraction?
Process using energy from ATP hydrolysis.
What is active transport?
Energy-dependent movement of substances across membranes.
What is protein synthesis?
Creation of proteins using energy from ATP.
What is the activation of molecules?
Increasing reactivity by adding phosphate group.
What is water?
Polar molecule acting as a solvent.
Define metabolite.
Substance involved in metabolic reactions.
What are cohesive forces?
Attraction between water molecules enabling column formation.
What are xylem vessels?
Plant structures transporting water upward.
What is surface tension?
Property allowing aquatic support for organisms.
What is latent heat of vaporization?
Energy required to convert water to gas.
What is specific heat capacity?
Energy needed to raise water temperature.
What are inorganic ions?
Dissolved ions with essential biological roles.
What do hydrogen ions (H+) affect?
Affect pH levels in solutions.
What is the role of iron ions (Fe2+)?
Crucial for oxygen transport in hemoglobin.
What is the role of sodium ions (Na+)?
Involved in glucose and amino acid transport.
What are phosphate ions (PO4^3-)?
Components of DNA, RNA, and ATP.
What is glucose transport?
Process utilizing sodium ions for absorption.
What is photosynthesis?
Process using light to produce ATP and glucose.
What is respiration?
Process converting glucose into ATP energy.
