Keyword definitions Flashcards
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What are AMINO ACIDS?
The monomers that make up proteins.
Describe the structure of AMINO ACIDS.
Has a central carbon atom that is bonded to a carboxylic acid group, an amino group, a hydrogen atom and an R group.
What is CONDENSATION?
A chemical process that joins monomers together.
What is usually lost in CONDENSATION?
A simple molecule (usually water)
Name 2 common products of CONDENSATION.
Biological polymers like polysaccharides and polypeptides.
What is a COVALENT BOND?
Bonding where 2 atoms share a pair of electrons
What is HYDROLYSIS?
Chemical process that breaks down larger molecules.
What is added in HYDROLYSIS?
Molecules broken by the addition of water.
What is a MONOMER?
A single smaller molecule that can form larger molecules.
What is a MONOSACCHARIDE, and what can they form?
A single sugar that can form carbohydrate polymers and dimers.
Give 3 examples of MONOSACCHARIDES.
Examples: glucose, fructose, galactose.
What is a NUCLEOTIDE made of?
A compound with an organic base and ribose sugar, linked to a phosphate group.
What are NUCLEOTIDES monomers of?
Is the monomer of nucleigc acids like DNA.
What are ORGANIC MOLECULES, and where can they be found?
Molecules containing carbon, found in living things.
Give 4 examples of ORGANIC MOLECULES.
Examples: carbohydrates, proteins, lipids, nucleic acids.
What is ALPHA GLUCOSE?
An isomer of glucose that can form starch or glycogen.
What is BETA GLUCOSE?
An isomer of glucose that can form cellulose.
What is CELLULOSE, and what is it made of?
A polysaccharide made of beta-glucose.
Where can CELLULOSE be found?
Can be found in plant cell walls.
What bonds is CELLULOSE made up of?
Contains B1-4 glycosidic bonds.
What monomer males up DISACCHARIDES? (simple)
Made of 2 monosaccharide units.
How do DISACCHARIDES form?
Formed by condensation.
What bonds make DISACCHARIDES?
Made of glycosidic bonds.
What is GLUCOSE, giving its chemical formula?
C6H12O6, a single sugar.
What are 2 uses of GLUCOSE?
Used in respiration, and the production of other molecules.
What is GLYCOGEN, stating one property of.
A highly branched polysaccharide.
What is GLYCOGEN made of?
Made of alpha-glucose.
Where is GLYCOGEN found?
Found in animal cells.
What bonds does GLYCOGEN contain?
Made from a1-4 and a1-6 glycosidic bonds.
What is a GLYCOSIDIC BOND?
Bond between sugar molecules.
Where are GLYCOSIDIC BONDS found?
Found in disaccharides and polysaccharides.
What is a HEXOSE SUGAR?
Sugars made of 6 carbons.
Do HEXOSE SUGARS have a set shape?
Does not need to be hexagonal.
What is a HYDROGEN BOND?
Chemical bond between positive hydrogen atoms and negatively charged atoms on adjacent molecules.
What do HYDROGEN BONDS usually form between?
Commonly between positive hydrogen and negative oxygen.
What is an ISOMER?
Compounds with the same formulae but different structures, giving them different properties.
What is a MONOSACCHARIDE?
A single sugar.
Give 3 examples of MONOSACCHARIDES.
Examples: glucose, fructose, galactose.
What is a NON-REDUCING SUGAR?
A sugar that cannot be used as a reducing agent.
Give an example of a NON-REDUCING SUGAR.
Example: sucrose.
What is a POLYSACCHARIDE?
Polymer made from many sugar units.
How do POLYSACCHARIDES form?
Formed by condensation.
How are monomers joined in POLYSACCHARIDES?
Monosaccharides joined by glycosidic bonds.
What are REDUCING SUGARS?
A sugar that can be used as a reducing agent (can donate electrons).
Give 3 examples of REDUCING SUGARS.
Examples: all monosaccharides, maltose and lactose.
What is STARCH?
A polysaccharide made of alpha glucose.
Where is STARCH found?
Found in plant cells.
What is STARCH made of? (2, plus bonds)
Made of amylose (a1-4 glycosidic bonds) and amylopectin (a1-4 and a1-6 glycosidic bonds).
What is GLYCEROL made of?
3 carbon chain with 3 hydroxyl groups.
What does GLYCEROL combine with to form triglycerides?
3 fatty acid chains.
What does GLYCEROL form when combined with 3 fatty acid chains?
1 triglyceride.
Define HYDROPHILIC.
Section of molecule that is attracted to water.
Define HYDROPHOBIC.
Section of molecule that repels water.
What are LIPIDS?
A class of organic compounds.
What are the derivitives of LIPIDS?
Fatty acids.
When are LIPIDS insoluble?
In water.
When are LIPIDS soluble?
In organic solvents.
Give 4 examples of LIPIDS (2 important).
Examples: triglycerides, phospholipids, waxes and steroids.
Define MONO-UNSATURATED FATTY ACID.
Fatty acid with a carbon chain that contains a single double bond between carbon atoms.
How many fatty acid molecules are there in PHOSPHOLIPIDS? (and how does this compare to triglycerides)
- triglycerides have 3.
What replaces the third fatty acid molecule in PHOSPHOLIPIDS?
A phosphate group (molecule).
When are PHOSPHOLIPIDS important?
Structure and function of plasma membranes.
Define POLY-UNSATURATED FATTY ACID.
Fatty acid molecule with mnay double bonds between carbon atoms.
Define SATURATED FATTY ACID.
A fatty acid molecule with no double bonds between the carbon atoms.
What is a TRIGLYCERIDE?
Individual lipid molecule.
What are TRIGLYCERIDES made of?
A glycerol molecule and 3 fatty acid molecules.
What bonds do TRIGLYCERIDES contain?
Ester bonds.
What is BENEDICT’S REAGENT?
Blue solution used in food tests.
What is BENEDICT’S REAGENT used to test for?
Both reducing and non-reducing sugars.
What is the BIRUET TEST?
Boichemical reaction to detect proteins.
What is a positive result for the BIRUET TEST?
Solution turns purple.
What is the EMULSION TEST for?
Test for lipids?
How do you carry out the EMULSION TEST?
Mix with ethanol (emulsify) THEN add water.
What is a positive result for the EMULSION TEST?
White cloudy emulsion (NOT precipitate) forms.
When is a NON-REDUCING SUGARS TEST conducted?
Following negaitive result from reducing sugars test.
How do you conduct a NON-REDUCING SUGARS TEST?
Heat with HCl (to hydrolyse into monosaccharides), then heat with Benedict’s solution.
What is a positive result for the NON-REDUCING SUGARS TEST?
Yellow to brick red precipitate forms.
How do you conduct a REDUCING SUGARS TEST?
Heat with Benedict’s solution.
What is a positive result in a REDUCING SUGARS TEST?
Yellow to brick red precipitate forms.
What reagent is used a REDUCING SUGARS or NON-REDUCING SUGARS TEST?
Benedict’s reagent.
What are AMINE GROUPS part of the structure of?
Amino acids.
What is an AMINE GROUPS made up of?
-NH2
What are CABOXYL GROUPS part of the structure of?
Amino acids.
What are CARBOXYL GROUPS made up of?
-COOH
What is a DISULFIDE BRIDGE?
Covalent bond formed between sulfur atoms.
Where are DISULFIDE BRIDGES found?
In R groups of amino acids.
What re IONIC BONDS between?
Bond between positive ion and negative ion.
What is a PEPTIDE BOND?
Bond formed between 2 amino acids.
What is a POLYPEPTIDE?
Many amino acids joined together.
What are POLYPEPTIDES joined by?
Peptide bonds.
What is PRIMARY PROTEIN STRUCTURE?
Sequence of amino acids that make up polypeptide chains.
What is a PROTEIN?
Polymer of amino acids joined by peptide bonds.
What is QUATERNARY PROTEIN STRUCTURE?
Number of polypeptide chains linked together, sometimes with non-protein groups to form a protein.
What is an R GROUP?
Group in amino acids that determines the bonding that it can do.
How many AMINO ACIDS are there?
20.
What is SECONDARY PROTEIN STRUCTURE?
The way the polypeptide chain is initially folded.
What is TERIARY PROTEIN STRUCTURE?
The entire folding of a polypeptide into a protein.
What determines TERTIARY PROTEIN STRUCTURE?
The amino acids that make up the chain.
Define ACTIVATION ENERGY.
Minimum energy required for a reaction to take place.
What is the ACTIVE SITE of an enzyme?
The region where the substrate binds to catalyse a reaction.
What is the ACTIVE SITE made up of?
Amino acids (you fool its a protein)
What does a COMPETITIVE INHIBITOR do to prevent enzymes functioning?
Binds to the active site to prevent substrates from binding.
How can the effects of COMPETITIVE INHIBITORS be negated?
Increasing the amount of substrate allows the rate of reaction to increase as they out-compete the inhobitor for the enzymes.
Define COMPLIMENTARY, in terms of enzymes.
Describes the relationship between the acive site and substrate, the way that the shapes fit together.
What is the function of an ENZYME?
Acts a a biological catalyst.
What type of molecules are ENZYMES?
Ensymes are proteins with a tertiary structure.
Define CATALYST.
Molecule that will lower the activation energy of a reaction without being used up in the process.
What is an ENZYME-SUBSTRATE COMPLEX?
The intermediate formed when a substrate interacts with the active site of an enzyme.
What is the INDUCED FIT MODEL?
A model to describe the interaction between enzymes and substrates.
Describe how the INDUCED FIT MODEL explains enzyme function.
As the substrate binds to the active site, the active site changes shape to form the enzyme-substrate complex.
What is an INHIBITOR?
A substance which reduces the activity of an enzyme.
Define KINETIC ENERGY.
The energy that particles have when in motion.
What is the LOCK AND KEY MODEL?
An analogy for the function of enzymes.
Describe how the LOCK AND KEY MODEL shows enzyme function.
Only the correctly shaped substrate key will fit into the the active site of the enzyme (lock).
Define METABOLISM.
All chemical reactions that take place in a living organism.
How does a NON-COMPETITIVE INHIBITOR prevent enzymes from functioning?
Substance binds at the allosteric site of an enzyme, putting pressure on its structure and causing the shape of the active site to change.
What is the ALLOSTERIC SITE of an enzyme?
Not the active site, where non-competitive inhibitors bind to.
What is pH used to describe?
Expressing the acidity or alkalinity of a solution.
What type of scale is the pH SCALE?
Logarithmic scale (each step goes up or down in a power of 10)
What are the min/max values of the pH SCALE, and what value is neutral?
1-14, 7 is neutral. Low numbers are acidic, higher numbers are alkaline.
What is the RATE OF REACTION used to describe?
The speed at which chemical reaction takes place.
How can the RATE OF REACTION be calculated?
The decrease in reactant/increase in product didvided by time.
Define SPECIFIC in terms of enzymes.
Describes how the enzymes catalyse only one reaction.
What is a SUBSTRATE?
A substance that is used by another substance or process. Will fit into a complimentary active site on an enzyme.
Define DELTA POSITIVE/NEGATIVE in terms of the charge of water.
A very slight positive/negative charge on an atom.
What is a POLAR MOLECULE?
Molecules that have an uneven distribution of charge.
Define COHESION within molecules.
Attraction between the same type of molecules.
Define ADHESION within molecules.
The tendency water molecules have to stick to surfaces or walls of tubes (like xylem)
Define SHC.
The amount of energy needed to raise 1kg of a substance by 1degree C
Define SPECIFIC LATENT HEAT.
The amount of energy needed for a substance to change state.
What is a CATABOLIC reaction?
A reaction that breaks down substrates.
What is an ANABOLIC reaction?
A reaction that joins substrates together.
What is the SATURATION POINT?
Where all enzyme active sites are filled.
Define DENATURED (enzymes)
When the tertiary structure of the enzyme is permanently changed.
What is ADP?
A nucleotide that can form ATP.
What does ADP join with to form ATP?
A phosphate group.
What reaction joins ADP and the phosphates?
Condensation reactions.
What are ADP reactions catalysed by?
ATP synthesase.
What does ADP stand for?
Adenosine diphosphate.
What does ATP stand for?
Adenosine triphosphate.
Where is ATP found? (broad)
All living organisms.
When is ATP produced?
ATP is produced in respiration.
What process is ATP important in?
The transfer of energy.
Define COMPLIMENTARY BASE PAIRING.
Sepcific rules for how bases match up.
What are the different pairs in COMPLIMENTARY BASE PAIRING?
C-G, A-T/U
As well as thymine, what does adenine also pair with in COMPLIMENTARY BASE PAIRING?
Uracil (U)
What does DNA stand for?
Deoxyribonucleic acid.
What is the function of DNA?
To store genetic information.
Describe directons of DNA.
The two strands are antiparallel.
How many strands foes DNA have?
2
What makes up the backbone of DNA?
Deoxyribose sugars and phosphate groups.
What shape is DNA?
Double helix.
How are the bases bonded in DNA?
Hydrogen bonds.
What type of sugar is found in DNA?
Deoxyribose sugar.
What are the organic bases in DNA?
Adenine, thymine, cytosine, guanine.
What type of molecule is DNA HELICASE?
Enzyme.
What is the function of DNA HELICASE?
Break the H-bonds between DNA bases and unwind the chain.
What type of molecule is DNA POLYMERASE?
Enzyme.
What is the function of DNA POLYMERASE?
Join the sugar phosphate backbones of new DNA strands.
What bonds do DNA POLYMERASE form?
Phosphodiester bonds.
What is DNA REPLICATION?
The process where DNA unwinds, the strand becomes a template for new DNA to form.
What is a DOUBLE HELIX?
The structure of DNA made of 2 strands of nucleotides.
What is a GENE?
A section of DNA coding for 1 or more polypeptide?
Where are GENES found?
On chromosomes.
What is the GENOTYPE?
All the genetic material found in an organism.
What is an ANTICODON?
Sequence of 3 nucleotides that is complimentary to a codon on mRNA.
Where are ANTICODONS found?
On tRNA.
What are CODONS?
Sequence of 3 nucleotides.
What is the function of CODONS?
Codes for a single amino acid.
What is MITOSIS?
A type of nuclear division where daughter cells have the same number of chromosomes as the parent cell.
What is a MUTATION?
A change in the genetic material of a cell.
What is a NUCLEOTIDE?
Monomer of nucleic acids.
What are NUCLEOTIDES made up of?
Organic base, sugar and phosphate group.
What are the 4 ORGANIC BASES?
Adenine, thymine, cytosine, guanine.
Where are ORGANIC BASES found?
In nucleotides.
What is a PENTOSE SUGAR?
A sugar with 5 carbons.
What is the PHENOTYPE?
The characteristics of an organism.
What affects the PHENOTYPE?
The genotype and the environment.
What is a PHOSPHODIESTER BOND?
A bond between the phosphate group of one nucleotide and the pentose sugar of another.
What is a POLYNUCLEOTIDE?
A polymer of nucleotides.
What is RNA?
A polynucleotide that has a ribose sugar rather than deoxyribose.
What bases does RNA contain?
Adenine, gyanine, cytosine, uracil.
What can RNA be?
mRNA, tRNA, rRNA.
What type of molecule is RNA POLYMERASE?
An enzyme.
What is the function of RNA POLYMERASE?
Joins together sugar-phosphate backbone of RNA molecules.
What is SEMI CONSERVATIVE REPLICATION?
The way DNA makes exact copies of itself, using the existing chain as a template.
What is TRANSCRIPTION?
Formation of mRNA from DNA that makes a particular gene.
What happens during ACTIVE TRANSPORT?
Substances are moved against a concentration gradient.
What type of process is ACTIVE TRANSPORT?
Active transport is an active process, requiring energy in ATP.
What is a BILAYER?
A membrane made of 2 layers.
What are BILAYERS made of?
Bilayers are made of phospholipids.
What is a CARRIER PROTIEN?
Binds and transports large molecules and ions across a phospholipid bilayer.
Where are CARRIER PROTEINS found?
Spanning a phospholipid bilayer.
What is a CELL SURFACE MEMBRANE?
A selctively permeable membrane that controls what goes in and out of the cell.
What is CHOLESTEROL?
A type of lipid.
Where is CHOLESTEROL an important component.
Cholesterol provides strengh to cell membranes.
What is the FLUID MOSAIC MODEL referring to?
The structure of the cell-surface membrane.
Describe the FLUID MOSAIC MODEL.
The phospholipid molecules can move relative to each other (fluid) and the embedded proteins can vary in size, shape and pattern (mosaic).
What is a GLYCOLIPID?
A carbohydrate covalently bonded to a lipid.
State 3 functions of GLYCOLIPIDS in cell membranes.
Recognitnion sites (antigens), molecular stability, help cells attach to each other.
What is a GLYCOPROTEIN?
Carbohydrate chains attached to a protein (extrinsic).
State 2 functions of GLYCOPROTEINS in context of cell surface membranes.
Recognition sites (antigens), help cells attach to each other.
Define PARTIALLY PERMEABLE.
Allows certian molecules through, typically smaller molecules like water and not large molecules like starch.
Define PERMEABILITY.
How easily a substance can pass through a membrane.
What factors contribute to PERMEABILITY?
Size, polarity, charge, lipid solubility.
What is a PHOSPHOLIPID?
A triglyceride where one of the fatty acid chains is replaced by a phosphate molecule.
What is a PLASMA MEMBRANE?
Membranes consisting of a phospholipid bilayer that surround cells and organelles.
What is a PROTEIN CHANNEL?
A water filled tube that allows water soluble proteins to pass through membranes.
Where are PROTEIN CHANNELS found?
Spanning cell membrane bilayers.
Define CONCENTRATION.
How much of a substance is dissolved in a solute.
Define DIFFUSION.
The net movement of particles across a membrane down a concentration gradient.
Where does DIFFUSION occur?
Across membranes.
Define SOLUTE.
The liquid part of a solution, that the solvent dissolves into.
Define CO-TRANSPORT.
Transport of 2 moleucles across a membrane in the same direction using the same carrier protein.
Define FACILITATED DIFFUSION.
Diffusion using channel and carrier proteins to allow large, polar or charged molecules across a membrane.
