Biochem - 1st Year with correct answers

Biochem - 1st Year All amino acids contain a central carbon, a side chain (R group), an amino group and a __________ group. - correct answer Carboxyl Amino acids can undergo a proton transfer, thus giving both a (+) and (-) charge. This molecular state is called the ________. - correct answer Zwitterion Amino acid that are unable to be synthesised from biochemical pathways within a cell have to be consumed through dietary intake. These are called _______ amino acids. - correct answer Essential When two amino acids join together, they are joined by an aide bond. This is also referred to as a _______ bond. - correct answer Peptide Which level of protein structure involves the amino acid sequence, but not the folding of the protein? - correct answer Primary Unfolding a protein using heat is a process called ________. This process does not affect the primary sequence of the protein. - correct answer Denaturation If a neutral amino acid is placed in a very basic environment (pH > 10), it will lose a proton (H+) from the __________ functional group. - correct answer Carboxyl - COOH Disulphides bonds are covalent bonds between two _______ amino acids. - correct answer Cysteine The process of breaking the bonds between amino acids within a polypeptide is called a ______ reaction. - correct answer Hydrolysis All amino acids contain both an acidic carboxyl group and a basic ______ group. - correct answer Amino Amino acids never exist in nature as neutral molecules; rather they undergo a proton transfer to form a ______. - correct answer Zwitterion Humans are unable to produce _____ of the amino acids required, and therefore they are referred to as essential amino acids. - correct answer 10 If an amino acid is placed in a very acidic environment (pH < 2) which functional group gains a proton (H)? - correct answer Carboxyl group The amino acid at the "ends" of the peptide can be either a N-terminal amino acid or a ________ amino acid. - correct answer C-terminal Which level of protein structure describes the 3D arrangement of localised regions? - correct answer Secondary structure Each turn in an alpha helix contains ____ (number) amino acid residues. - correct answer 3.6 Some enzymes, such as pepsin, break down polypeptides by ______. - correct answer Hydrolysis Various processes, including heating, can achieve disruption of secondary, tertiary, and even quaternary protein structure. This type of change in a proteins shape is termed ______ . - correct answer Denaturation There are _____ amino acids that humans must obtain from diet and can't produce. - correct answer 10 All amino acids contain the acidic _____ group and a basic amino group - correct answer Carboxyl Amino acids never exist in nature as neutral molecules; they undergo a ______ transfer to from a zwitterion. - correct answer Proton In the Fischer projections when L and D isomers can be identified by the position of NH3+ group, _____ isomers are considered common naturally occurring amino acids. - correct answer L isomers If an amino acid is placed in an environment with pH around 6, they will exist in their ______ form. - correct answer Zwitterion Which structure of protein shows the sequence of amino acids that form the protein? - correct answer Primary ______ bonds are covalent bonds that help stabilise the tertiary structure of protein. - correct answer Disulfide The first step in digestion of protein involves some enzymes such as pepsin in a process called ______. - correct answer Hydrolysis Some enzymes require an additional molecule to be present in order for the reaction to take place. This additional molecule is called a ________. - correct answer Co-factor Enzymes that are highly specific for a single substrate are best described as the _______ model of enzyme/substrate interaction? - correct answer Lock-and-key Which group of enzymes do reductases belong to? - correct answer Oxidoreductases The transfer of a phosphate group to a molecule is catalyzed by which class of enzyme? - correct answer Kinase Which enzyme control is characterised by the binding of a regulator molecule to the enzyme causing a conformational change that increases the ability of the active site to bind substrate. - correct answer Positive allosteric control Does a competitive inhibitor bind to the active site of the target enzyme? - correct answer Yes Is noncompetitive inhibition a form of reversible or irreversible inhibition? - correct answer Form of reversible inhibition Pepsinogen is an example of an enzyme that is produced in its inactive form and later undergoes modification to make it active. These types of inactive precursors of enzymes are called ______. - correct answer Zymogen Enzymes perform the role of _______? - correct answer Biological catalysts What is the classification of enzymes that cleve bonds with water? - correct answer Hydrolases Which group of enzyme can be said to create bonds accompanied by energy release from a hydrolysis reaction? - correct answer Ligases What functional group do kinase enzymes transfer? - correct answer Phosphate group Which type of enzyme control is characterised by the binding of a regulator molecule to the enzyme causing a conformational change that decreases the ability of the active site to bind substrate? - correct answer Negative allosteric control Does a non-competitive inhibitor bind to the active site of the target enzyme? - correct answer Doesn't bind to active site Enzymes that catalyse the addition or removal of a molecule to create or remove a double bond are classified as _____? - correct answer Lyases Enzymes that catalyse bond formation accompanied by energy release from a hydrolysis reaction are classified as _____ ? - correct answer Ligases Enzymes that can act on a wide range of substrates and can adjust to the shape of substrate are explained by the _____ model of enzyme/substrate interaction. - correct answer Induced-fit The temperature that enzymes often have their maximum reaction rate is around ______? - correct answer 37 c ______ control is characterised by the binding of a regulator molecule to the enzyme causing a conformational change that decreases the ability of the active site to bind substrate. - correct answer Negative allosteric control _____ bind and stop the enzyme which permanently stop its activity. - correct answer Irreversible inhibitor A nucleoside is composed of a monosaccharide and a ______ - correct answer Nitrogen containing base Which group of nitrogen-containing bases is known for their 1-ring structure? - correct answer Pyrimidine What is the full name of the monosaccharide found in RNA? - correct answer D-ribose True/False - Steroids and phospholipids are not able to be broken down into smaller components via hydrolysis. - correct answer False How many nucleotides are used in RNA? - correct answer Four What type of receptor is the nicotinic acetylcholine receptor? - correct answer Ion channel What occurs when acetylcholine binds to the nicotinic acetylcholine receptor? - correct answer Opening of the channel and release of ions What is the term used to describe the fact there are multiple codons encoding for the same amino acid? - correct answer Redundancy dAMP is an abbreviation for which nucleotide? - correct answer Deoxyadenosine 5' monophosphate In a DNA molecule, what nucleotide is the complementary base for Adenine? - correct answer Thymine How many nucleotides make up a codon? - correct answer 3 nucleotides Three stages of protein synthesis? - correct answer initiation, elongation, termination Which group of nitrogen-containing bases is known for their 2-ring structure? - correct answer Purine What is the full name of the monosaccharide found in DNA? - correct answer D-2- deoxyribose CMP is an abbreviation for which nucleotide? - correct answer Cytidine 5' monophosphate Which carbon atom of a nucleoside does the phosphate group bind to in order to create a nucleotide? - correct answer 5th carbon DNA had a _____-handed double helix structure - correct answer Right How many codons code for amino acids? - correct answer 61 Nuclei acids are unbranded polymers composed of repeating monomers called _____? - correct answer Nucleotides RNA contains _____ instead of thymine - correct answer Uracil ATP is an abbreviation for which nucleotide? - correct answer Adenosine 5'-triphosphate The _____ group binds the 5' carbon atom of a nucleoside in order to create a nucleotide. - correct answer Phosphate The double helix in DNA is stabilised by _______ bonding between bases. - correct answer Hydrogen Messenger RNA (mRNA) carries information from DNA to _____? - correct answer Ribosome Monosaccharides generally contain from ____ to ____ carbon atoms. - correct answer 3 to 6 Monosaccharides are known to contain a ____ functional group at either C1 or C2 atoms/ - correct answer Carbonyl Which carbon atom contains a ketone functional group in ketone molecules? - correct answer C2 bond between two monosaccharides is called a _____ linkage. - correct answer Glycosidic How many carbon atoms are present in a tetrose molecule? - correct answer 4 How many carbon atoms are present in a triose molecule? - correct answer 3 How many carbon atoms are present in a pentose molecule? - correct answer 5 How many carbon atoms are present in a hexose molecule? - correct answer 6 Is glycogen a branded or unbranced polymer? - correct answer Unbranched Which polysaccharide is the major form produced by humans? - correct answer Glycogen A monosaccharide is a ketopentose if it has a _____ functional group and _____ carbon atoms. - correct answer Ketone; 5 When two monosaccharides join to form a disaccharide the bond occurs between the _____ carbon atom on the first molecule and the _____ carbon atom on the second molecule. - correct answer C1 and C4 The glucose molecule can exist in equilibrium as 3 different forms. What term is used to describe this? - correct answer Mutarotation A monosaccharide is called ketoses if it has a ketone group at the _____ carbon atom. - correct answer C2 When the orientation of a disaccharides is in a way that the glycoside bond is down, it is _____ glycoside. - correct answer Alpha The non-polar nature of lipids comes from the large number of C-H and _____ bonds? - correct answer C-C What are the two categories of lipids? - correct answer Hydrolyzable and nonhydrolyzable lipids hydrolysable lipids include waxes, phospholipids and ________? - correct answer Triglycerols Waxes are esters formed from the reaction of a high molecular weight alcohol and a _______? - correct answer Fatty acid Oils have a lower melting point compared to fats because they have ______ double bonds in their structure. - correct answer More Triacylglycerols are composed of a ______ molecule bound to three molecules of fatty acids. - correct answer Glycerol Fats have a higher melting point compared to oils because they have ____ double bonds in their structure. - correct answer Less Which type of phospholipid does not contain a glycerol backbone? - correct answer Sphingomyelin Do naturally occurring fatty acids have an odd or even number of carbon atoms? - correct answer Even Waxes are esters formed from the reaction of a fatty acid and a _____ - correct answer Alcohol Steroids are a class of lipids that are characterised by having a carbon skeleton consisting of ____ six-membered rings and one five-membered ring. - correct answer Three What is the relationship between the number of double bonds and the melting temperature of a fatty acid? - correct answer Increase in number of double bonds = decrease in melting point Lipids contain a large number of c-c and c-h bonds. Does this mean they are polar or non-polar? - correct answer Non-polar Lipids are identified based on the fact that they are soluble in organic solvents, but insoluble in water. True/false - correct answer True True/False - lipids contain a large number of carbon-oxygen and oxygen-oxygen bonds. - correct answer False True/false - naturally occurring fatty acids have even numbers of carbon atoms. - correct answer True True/false - anabolic reactions involve the release of energy? - correct answer False The hydrolysis of ATP to form ADP releases a significant amount of energy. How much energy is released by 1 mole of ATP being hydrolysed to form ADP? - correct answer 7.3 k/cal mol of energy The breakdown of larger molecules into smaller ones is termed ____? - correct answer Catabolism End products of citric acid cycle? - correct answer 2 x CO2 1 x GTP 1 x FADH2 3 x NADH In the first step of the citric acid cycle oxaloacetate reacts with what molecule to produce citrate? - correct answer Acetyl CoA How many enzyme complexes are involved in the electron transport chain? - correct answer 4 What is the term for the process of converting ADP to ATP? - correct answer phosphorylation The synthesis of larger molecules from smaller ones is termed _____? - correct answer Anabolism What is the 4-carbon molecule that Acetyl CoA reacts with in the 1st step of the citric acid cycle? - correct answer Oxaloacetate The catabolisation of amino acids requires that the NH3 group be removed first, which is achieved via a two-step process of transamination followed by _______? - correct answer Oxidative deamination Conversion of 1 mole of ADP to ATP requires _____ kcal energy. - correct answer 7.3 Energy production occurs in the _____ of the cells. - correct answer Mitochondria Is the catabolism of fatty acids a linear, cyclic, or spiral pathway? - correct answer Spiral The reactions where the energy released by one provides the energy to drive the other reaction are called ______ reactions. - correct answer Coupled True/false - molecules that are nonpolar, non-charged, or hydrophobic are generally able to cross the plasma membrane via simple diffusion. - correct answer True What property of steroid molecules allows them to cross the plasma membrane easily? - correct answer Hydrophobic Does facilitated diffusion require the input of energy in order to transport a solute across the membrane? - correct answer No energy input required The sodium-potassium pump moves Na+ and K+ across the membrane. How many K+ ions are transported at one time? - correct answer 2x K+ sodium-potassium pump requires that _____ (number) of Na + ions bind before it can pump them across. - correct answer 3x Na+ In secondary active transport, often the target solute/substance is transported across the membrane at the same time another substance is also transported. What is the name of a carrier protein that transports both molecules in the same direction across the membrane? - correct answer Symporter What is the name of the carrier protein that transports both molecules in opposite directions across the plasma membrane? - correct answer Antiporter Cells are able to bring substances into the cell via a process known as _____, which involves the plasma membrane engulfing the substances to be carried into the cell. - correct answer Endocytosis Cells are able to bring fluid with dissolved solutes into the cell by a process termed ______. - correct answer Pinocytosis Cells are able to remove substances from the cell by fusing vesicles with the cell membrane to eject the substances to the external environment. This is called _____ - correct answer Exocytosis ______ are small spherical sacs made from the membrane that are involved in transporting substances inside and outside cells. - correct answer Vesicles An ammonium ion is a nitrogen atom bound to how many organic (R) groups? - correct answer 4 The neurotransmitter dopamine is derived from which amino acid? - correct answer Tyrosine For the conversion of L-dopa to dopamine, what functional group is replaced by a single hydrogen? - correct answer COOH - Carboxyl group Tryptophan is a precursor amino acid for which neurotransmitter? - correct answer Serotonin What kind of molecule is acetylcholine? - correct answer Quaternary Ammonium ion When a nitrogen atom is bound to four organic groups, it exists as a ________? - correct answer Quaternary ammonium ion The reaction of an amine with a carboxylic acid derivative, results in what type of molecule? - correct answer Water soluble ammonium ion For the conversion of tyrosine to L-dopa what single functional group is added to the tyrosine molecule? - correct answer Hydroxyl group When amines react with _____ an ammonium salt is formed - correct answer Acid What is the common structure that is found in many physiological compounds, including noradrenaline, adrenaline, amphetamine, and methamphetamine? - correct answer 2-phenylethylamine Amide bonds are formed by ________ to join amino acids together. - correct answer Condensation reactions Some cofactors serve as oxidising agents, some serve as reducing agents and some serve other purposes. What reaction is FAD involved in? - correct answer Oxidation reactions Some cofactors serve as oxidising agents, some serve as reducing agents and some serve other purposes. What reaction is NADH involved in? - correct answer Reducing agent Some cofactors serve as oxidising agents, some serve as reducing agents and some serve other purposes. What reaction is NAD+ involved in? - correct answer Oxidation reactions The monosaccharides that make up cellulose are joined together by which form of bond? Alpha or beta? - correct answer Beta glycosidic linkage True/false - Waxes and phospholipids are able to be broken into smaller molecules via hydrolysis? - correct answer True What is the term for the process by which fatty acids are catabolised? - correct answer Beta-oxidation What is the classification of enzymes that catalyse the cleave of single bonds using H2O molecule? - correct answer Hydrolases Monosaccharides that make up amylose are joined together by which form of bond? Alpha or beta? - correct answer Alpha Messenger RNA (mRNA) carries info from DNA to _____? - correct answer Ribosome Hydrolyzable lipids? (Hint-3 of them) - correct answer Waxes, triacylglycerols and phospholipids nonhydrolyzable lipids? (Hint-3 of them) - correct answer Steroids, fat-soluble vitamins and eicosanoids Waxes are esters formed from the reaction of a fatty acid and a ______? - correct answer Alcohol What neurotransmitter is a quaternary ammonium ion and acts between neurones and muscle cells? - correct answer Acetylcholine True/false- lipids are identified based on the fact that there are very long hydrocarbon chains attached to polar heads? - correct answer False The complete catabolism do glucose results in a yield of how many ATP molecules? - correct answer 32 ATP Is glycolysis a linear, cyclic or spiral pathway? - correct answer Linear Which level of protein structure describes the 3D arrangement of multple, seperate polypeptide strands to form the final protein complex? - correct answer Quaternary Name the DNA nucleoside derived from cytosine base - correct answer Pyrimidine In the cyclic form of glucose, which carbon atom is known as the anomeric carbon? - correct answer C1 When mutarotation is occurring, the glucose molecule can exist in 3 different forms, including alpha & beta anomeric forms. What is the third form? - correct answer Linear What type of reaction takes place when two amino acids join together to form an amide bond? - correct answer Condensation reaction Enzymes that are able to act on a wide range of substrates, but are specific for a single type of reaction, can be explained by which model of enzyme/substrate interaction? - correct answer Induced-fit Is noncompetitive inhibition reversible or irreversible inhibition? - correct answer Reversible Cellulose is an unbranced polymer of which monosaccharide? - correct answer Glucose A codon is sequence of how many amino acids? - correct answer 1 Depending on the R group an amino acid can be classified as ____ when additional COOH group is in the side chain - correct answer Acidic Cellulose is composed of glucose rings joined together with ____ glycoside linkage - correct answer Beta The 'n' in an omega-n fatty acid refer to the carbon where the first double-bond occurs from the ____ end of the fatty acid chain. - correct answer CH3 True/False - Coenzyme A is a reducing agent - correct answer False When energy is requires for transport, it is provided by hydrolysis of _____ - correct answer ATP The neurotransmitter dopamine is a direct precursor to which other neurotransmitter? - correct answer Norepinephrine When acetylcholine binds to the muscarinic acetylcholine receptor it cause _____ to occur. - correct answer A cascade of signals within cell