Why is the isolation of biomolecules in pure form important?
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To determine the function of the biomolecule.
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Why is the isolation of biomolecules in pure form important?
To determine the function of the biomolecule.
What is necessary to purify a biomolecule to homogeneity?
A combination of successive use of several methods.
What are the most frequent reactions encountered in biochemical processes?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What are the three major components of the experimental approach used in biochemistry?
What is the functional group of Asparagine?
Amido (-CONH2)
What is meant by purifying a biomolecule to homogeneity?
Freedom from contamination by any other biomolecule.
What is the basic unit of biology?
The cell.
What is the family name of the functional group in Asparagine?
Amide (R-CONH2)
What does gas-liquid chromatography (GLC) and thin-layer chromatography (TLC) allow the extensive study of?
Lipids.
What did the use of electron microscope reveal in cellular components?
Many previously unknown or poorly observable components.
Why is the rat hepatocyte extensively studied from a biochemical standpoint?
Due to its availability in relatively large amounts, suitability for fractionation studies, diversity of functions, and containing major organelles found in eukaryotic cells.
What is the next step after purifying a biomolecule?
Determining its structure.
What is the significance of the functional group in Asparagine?
Polar, but does not bear a charge. Participates in H-bond formation.
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What did the introduction of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) make possible?
Analysis of membrane and many other proteins.
What is subcellular fractionation?
A biochemical method involving centrifugation to separate cellular components.
What makes certain enzymes powerful tools in determining the structural features of biomolecules?
The known specificity of certain enzymes.
What method permitted the isolation and analysis of cellular components in vitro?
Disruption and ultracentrifugation.
What was the initial level of biochemical research on humans and animals?
At the level of the whole animal.
What does determining the structure of a biomolecule allow?
Detailed correlations to be made between structure and function.
What are the major organelles found in a rat hepatocyte?
Nucleus, mitochondria, endoplasmic reticulum, free ribosomes, Golgi apparatus, lysosomes, peroxisomes, plasma membrane, and certain cytoskeletal elements.
What is the purpose of homogenization in subcellular fractionation?
To disrupt cells under mild conditions and extract organelles.
What is the use of measurement of blood T4 or TSH in the neonatal diagnosis of congenital hypothyroidism?
To act as screening tests for the early diagnosis of congenital hypothyroidism.
What is an example of an addition reaction in biochemical processes?
Hydration, such as the hydration of fumarate to form malate.
What did the introduction of the detergent SDS permit for electrophoresis?
The solubilization of many proteins that were previously insoluble.
What is the functional group in the given biomolecule?
Carboxyl (-COOH).
What is the aim of Biochemistry?
To describe and explain, in molecular terms, all chemical processes of living cells.
What was the initial level of biochemical research on humans and animals?
At the level of the whole animal.
Why is it necessary to isolate organelles in relatively pure form?
To study their function in detail, free of significant contamination by other organelles.
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What are the major constituents of the three fractions obtained through subcellular fractionation?
Nuclei, mitochondria, and microsomes.
What are some of the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What are the routine methods of choice for structural determination in biochemical methods?
Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy.
How are organs and their cells disrupted during the process of homogenization?
By rotating a manually operated or motor-driven pestle within a glass tube containing minced fragments of the organs and a homogenizing medium.
What is the purpose of Table 1 - 5 in biochemistry?
To list the major methods used to analyze the structures of biomolecules.
Why was it realized that the whole animal was too complex for definitive answers in biochemical research?
Because it presented many complications.
What are some of the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What are the major constituents of most biomolecules?
Carbon, hydrogen, oxygen, and nitrogen.
How is the progress of infectious hepatitis monitored?
By using the plasma enzyme alanine aminotransferase (ALT).
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What does Biochemistry encompass?
Large areas of cell biology, molecular biology, and molecular genetics.
What is the chemical formula for the aldehyde functional group?
-CHO
Why was the whole animal considered too complex for definitive answers in biochemical research?
It was too complex to permit definitive answers to many questions.
What is the functional group represented by H2N-C-COOH?
Amino group (-NH2).
Why is isolation of biomolecules in pure form important?
To determine the function of any biomolecule.
What is the structure of the ketone functional group?
C - CO - C.
What is a marker enzyme or chemical in the context of subcellular fractionation?
An enzyme or chemical almost exclusively confined to one particular organelle, indicating the presence or absence of that organelle in a fraction.
What is the family name of the functional group -COOH?
Carboxylic acid (R-COOH).
What are the chief components of the human body?
Protein, fat, carbohydrate, water, and minerals.
What is the method used for fractionation of the contents of the homogenate?
Differential centrifugation.
What type of reaction involves the transfer of electrons?
Oxidation-reduction (redox) reactions.
What are the most frequent reactions encountered in biochemical processes?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
How are the structures of many proteins and complex carbohydrate chains determined?
By high-resolution NMR spectroscopy.
What is the structure of the Ester functional group?
R―C―O―R’
What determines the chemical properties of organic molecules?
Specific arrangement of atoms called functional groups.
What are the three physical techniques required for subcellular fractionation?
Extraction, Homogenization, Centrifugation.
What forces are exerted on cells during homogenization?
Mechanical shearing forces.
What is the process of nucleophilic substitution reaction?
A nucleophile (A:) replaces a leaving group (X:) in a molecule (B‒X) to form a new compound (A‒B).
What preparations were developed to simplify biochemical research?
Simpler in vitro preparations.
Why is it necessary to extract a specific organelle or molecule from cells?
To isolate and study it.
What are the major complex biomolecules found in cells and tissues of higher animals?
Nucleic acids (DNA and RNA), proteins, carbohydrates (polysaccharides), and lipids.
How does WHO define health?
As a state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity.
What type of reaction forms a double bond by removing atoms from a molecule?
Elimination reaction.
What is the functional group represented by -SH?
Sulfhydryl.
Which element is a component of nucleic acids and other molecules, and is widely distributed in its ionized form in the human body?
Phosphorous.
What is the focus of Biochemistry?
The chemistry of living organisms and the chemical constituents of living cells.
What do isomerization reactions involve?
The intramolecular shift of atoms or groups.
What is the reciprocal relationship between biochemistry and medicine?
All diseases are manifestations of abnormalities of molecules, chemical reactions, or processes, hence a reciprocal relationship exists.
What is the purpose of determining the structure of a biomolecule?
To allow detailed correlations to be made between structure and function.
What preparations were developed to simplify biochemical research?
Simpler in vitro preparations.
What is the purpose of measuring blood carcinoembryonic antigen (CEA) in certain patients who have been treated for colon cancer?
To assist in assessing the responses of diseases to therapy.
In which biomolecules is the aldehyde functional group found?
Carbohydrates (aldoses)
What is the family name for the functional group R-NH2?
Amine (R-NH2).
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What is necessary to purify a biomolecule to homogeneity?
A combination of successive use of several methods.
What is the family name for the ketone functional group?
Ketone (R - CO - R’).
How many different centrifugation steps are used in the classic differential centrifugation method?
Three different centrifugation steps at successively greater speeds.
What is the structure of the Ester functional group?
R―C―O―R’
What is the significance of the carboxyl functional group?
It is polar and participates in H-bond formation. It is weakly acidic and bears a negative charge when it donates a proton.
Which method provides the most detailed information about the structure of biomolecules?
X-ray diffraction and crystallography.
What is the role of AH2 in the oxidation-reduction reaction?
AH2 acts as a reducing agent.
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What is the resulting solution called after homogenization?
Homogenate, which contains many intact organelles.
What is the major component of the human body?
Water.
What do the various preparations summarized in Table 1-6 allow to study?
Biochemical processes.
What is the family name of the Ester functional group?
Ester (R - COOR’)
What are the two types of metabolic processes?
Catabolism and Anabolism.
What happens in an addition reaction?
Two molecules combine to form a single product.
What happens when hydrogen atoms on organic molecules are replaced by different functional groups?
Different families of organic compounds result.
What organ was often used for pioneering work in subcellular fractionation?
Rat liver.
What is the functional group of hydroxyl?
-OH
What are the building blocks of nucleic acids?
Nucleotides.
What is subcellular fractionation?
The process of isolating organelles from cells using centrifugation and different homogenization media.
What is the biochemical viewpoint of health?
A situation in which all intra- and extracellular reactions in the body are proceeding at rates in proportion with its maximal survival in the physiologic state.
What conditions are necessary for the extraction of organelles and biomolecules?
Mild conditions, such as the use of aqueous solutions, avoidance of extremes of pH and osmotic pressure, and avoidance of high temperatures.
What are the primary functions of metabolism?
Acquisition and utilization of energy, synthesis of molecules needed for cell structure and functioning, and removal of waste products.
What does Biochemistry attempt to understand?
How life began.
What are the major methods used to analyze the structures of biomolecules?
Elemental analysis, spectroscopy, acid/alkaline hydrolysis, enzyme degradation, mass spectrometry, specific sequencing methods, and X-ray crystallography.
What is the family name for the functional group R-SH?
Thiol.
What is the functional group of the organic biomolecule Alkene?
Alkenyl (-CH=CH-).
What does the isolated perfused organ method allow the study of?
An organ removed from the influence of other organs or the nervous system.
Which element plays a key role in numerous biologic processes?
Calcium.
What are the major organic biomolecules of the human body?
Nucleic acids, proteins, lipids, and carbohydrates.
What is one of the most common biochemical isomerization reactions?
The interconversion between aldose and ketose sugars.
What does the nuclear fraction mostly contain?
Nuclei, plasma membrane, and unruptured cells.
What is the significance of the aldehyde functional group?
It is polar and participates in H-bond formation.
What is the significance of the amino functional group?
It is polar and participates in H-bond formation. It is weakly basic and bears a positive charge when it accepts a proton.
What are the major methods used to separate and purify biomolecules?
Salt fractionation, chromatography, electrophoresis, ultracentrifugation, and others.
What are the most frequent biochemical reactions?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What is hydrolysis?
The cleavage of a covalent bond by water.
What does each step of the classic differential centrifugation method yield?
A pellet and a supernatant.
What is the method used for fractionation of the contents of the homogenate?
Differential centrifugation.
What is an example of an elimination reaction in biochemistry?
The dehydration of 2-phosphoglycerate to form phosphoenolpyruvate.
What is the significance of the ketone functional group?
It is polar and participates in H-bond formation.
What is the family name of the Ester functional group?
Ester (R - COOR’)
What are the major causes of diseases related to immunologic reactions?
Anaphylaxis and autoimmune diseases.
What is the role of O2 in the oxidation-reduction reaction?
O2 acts as an oxidizing agent.
What is the role of NAD+ in the oxidation-reduction reaction?
It acts as an oxidizing agent.
What allows water to function as a solvent in the human body?
Its polar nature and ability to form hydrogen bonds.
What is the significance of the Ester functional group?
It is polar and participates in H-bond formation.
What does STKM stand for in the context of subcellular fractionation?
STKM stands for a solution consisting of 0.25 M sucrose, adjusted to pH 7.4 by 0.05 M TRIS (tris - [hydroxymethyl]aminomethane) HCl buffer, and K+ and Mg2+ at near physiologic concentrations.
What is catabolism?
A set of metabolic pathways that breaks down molecules into smaller units, which are either oxidized to release energy, or used in other reactions.
Name the frequently encountered and important functional groups in organic biomolecules.
Hydroxyl, Aldehyde, Ketone, Carboxyl, Ester, Amino, Amido, Sulfhydryl, Alkenyl.
What are the most frequent reactions encountered in biochemical processes?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What is the family name for the functional group R-OH?
Alcohol
What are the building blocks of proteins?
Amino acids.
What is the use of acid or alkaline hydrolysis in determining the structure of biomolecules?
To degrade the biomolecule under study into its basic constituents.
At what temperature are most procedures for isolating organelles performed?
About 0 to 4 °C.
How have modifications of centrifugation allowed the isolation of organelles?
By using different homogenization media or protocols.
What are the major prerequisites for the maintenance of health?
Optimal dietary intake of vitamins, nutritionally essential amino acids, nutritionally essential fatty acids, various minerals, water, and carbohydrates.
What is the significance of the sulfhydryl group in biomolecules?
It does not participate in H-bond formation and is less soluble in water than alcohols.
Which organs are particularly suitable for the isolated perfused organ method?
Liver, heart, and kidney.
What is the role of biochemical investigations in relation to diseases?
To reveal the fundamental causes and mechanisms of diseases.
Why do the thousands of reactions that occur in cells appear overwhelming at first look?
Due to the large number of reactions.
What is the family name of the functional group Alkenyl?
Alkene (R-CH=CH-R').
What type of diseases are sickle-cell anemia, atherosclerosis, and diabetes mellitus?
Genetic diseases.
Name some elements encountered on an almost daily basis in medical practice in dealing with patients with electrolyte imbalances, iron-deficiency anemia, and thyroid diseases.
Potassium, sulfur, sodium, chlorine, magnesium, iron, manganese, and iodine.
How are biomolecules precipitated in salt fractionation?
By precipitation with ammonium sulfate.
What is mostly found in the mitochondrial fraction?
Mitochondria, lysosomes, and peroxisomes.
What is the family name for the aldehyde functional group?
Aldehyde (R-CHO)
How many pellets are yielded in the classic differential centrifugation method?
Three pellets.
What are the three pellets obtained from the overall procedure of classic differential centrifugation?
Nuclear, mitochondrial, and microsomal fractions.
What happens in an elimination reaction involving biomolecules with a hydroxyl functional group?
The removal of H2O.
What is the product of an oxidation-reduction reaction involving pyruvate and NADH?
Lactate, NAD+ and a reducing agent.
What are the major causes of diseases related to nutritional imbalances?
Deficiencies and excesses.
What type of reactions are usually involved in hydrolysis?
Nucleophilic substitution either at a saturated carbon or a carbonyl carbon.
What is the significance of the Ester functional group?
It is polar and participates in H-bond formation.
Where is the ketone functional group found in biomolecules?
In carbohydrates (ketoses) like D-Fructose.
What was the initial level of biochemical research on humans and animals?
The level of the whole animal.
What is the role of NADH in the oxidation-reduction reaction?
It acts as a reducing agent.
What is the next abundant component after water in the human body?
Protein.
Where are Ester functional groups found?
In certain lipids.
What are the components of the STKM solution used for extraction of organelles?
0.25 M sucrose, 0.05 M TRIS HCl buffer, K+ and Mg2+ at near physiologic concentrations.
What is anabolism?
A set of metabolic pathways that construct or build molecules from smaller units.
Are lipids polymers of fatty acids?
No, lipids are not polymers of fatty acids.
How is mass spectrometry used in determining the structures of biomolecules?
It is used to analyze the mass and composition of biomolecules.
What is the significance of the hydroxyl functional group?
It is polar and participates in H-bond formation.
What can cause significant losses of activity during extraction at room temperature?
The action of various enzymes that are released when cells are disrupted.
What is a nucleophile?
A species that is attracted to an electrophile and substitutes one atom or group for another.
What are polysaccharides made up of?
Simple carbohydrates (monosaccharides).
What is the applicability of the described procedure for subcellular fractionation?
It is applicable in general to most organs and cells.
What is the structure of L-Cysteine?
H2N-C-COOH with CH2SH side chain.
How are biochemical investigations used to demonstrate the nature of genetic defects in cystic fibrosis?
By revealing the nature of the genetic defects.
What allows simplifying the overall picture of metabolism?
The relatively small number of reaction types, simple mechanisms used in biochemical reactions, and the relatively few number of reactions of central importance.
What is the significance of the Alkenyl functional group in biomolecules?
It is an important structural component, such as in lipids.
What does the sequential use of several techniques generally permit?
Purification of most biomolecules.
What are the names of the three pellets obtained in the classic differential centrifugation method?
Nuclear, mitochondrial, and microsomal fractions.
What are the two types of metabolic processes?
Catabolism and anabolism.
What does the microsomal fraction (microsomes) mostly contain?
A mixture of SER, RER, and free ribosomes.
What are the major causes of diseases in biochemistry?
Physical agents, chemical agents, biologic agents, lack of oxygen, and genetic disorders.
What is the role of NADH in the oxidation-reduction reaction?
It acts as a reducing agent.
What are the major causes of diseases related to hormonal imbalances?
Hormonal deficiencies and excesses.
Where is the Ester functional group found?
In certain lipids.
How is the digestion of proteins in the stomach catalyzed?
In acid-catalyzed reactions.
Why was the whole animal considered too complex for definitive answers in biochemical research?
It presented many complications.
What is the order of abundance of components in the human body after water?
Protein, fat, minerals, and carbohydrates.
How are organic solvents used in subcellular fractionation?
Organic solvents are used for the extraction of lipids and nucleic acids.
What is a metabolic pathway?
A series of reactions responsible for the synthesis of a more complex compound from one or more simple compounds (anabolic), or for the degradation of a compound to its end product (catabolic).
What aspects of chemistry does biochemistry combine?
All the fields of chemistry.
What are biopolymers composed of?
Repeating units of their building blocks.
What is the purpose of specific sequencing methods in determining the structures of biomolecules?
To determine the sequence of proteins and nucleic acids.
Who established the cell as the fundamental unit of biologic activity in the 19th century?
Schleiden, Schwann, and other pioneers such as Virchow.
What is the approximate percentage of carbon in the human body on a dry weight basis?
50%.
What are nucleophiles most commonly?
Negatively-charged atoms or groups.
What is the principal monosaccharide found in human tissues that makes up glycogen?
Glucose.
How can cell fractions obtained through subcellular fractionation be assessed?
By measuring marker enzymes and chemicals, and by using the electron microscope.
What is the speed and duration of the third centrifugation step in the classic differential centrifugation method?
105,000 g for 60 minutes.
Where is the hydroxyl functional group found?
In carbohydrates.
How are biochemical investigations used to suggest rational treatment of diseases?
By recommending specific treatments based on biochemical findings.
What are the most frequent reactions encountered in biochemical processes?
Nucleophilic substitution, elimination, addition, isomerization, oxidation-reduction (redox), and hydrolysis reactions.
What do the contents of the final supernatant correspond to?
Those of the cytosol (cell sap).
What is the normal chemical composition of water in a 65-kg man?
40 kg, which is 61.6% of the body mass.
What are the two configurations of the Alkenyl functional group?
cis and trans configuration.
Define catabolism.
A set of metabolic pathways that breaks down molecules into smaller units, which are either oxidized to release energy, or used in other reactions.
Give examples of physical agents that can cause diseases.
Mechanical trauma, extreme temperature, sudden changes in atmospheric pressure, radiation, electric shock.
What is the role of NAD+ in the oxidation-reduction reaction?
It acts as an oxidizing agent.
How do the major causes of diseases influence the body?
By influencing various biochemical mechanisms in the cell or in the body.
What important cellular process is driven by breaking the phosphate bonds of ATP?
Many cellular processes.
What preparations were developed to remove complications experienced at the level of the whole animal?
Simpler in vitro preparations.
What is the importance of biochemistry in genetics?
Biochemistry of nucleic acids is at the heart of genetics.
