Share
Explore BrainMass

Cell BioChem

Cell biochemistry studies chemical reactions and processes that occur in and between biological cells, such information can deepen understanding on the emergent properties of an organism. Cell Biochemistry is highly interdisciplinary topic as it shares important concepts with Molecular Biology and Genetics. Biochemical reactions occur on all scales, from cells, tissues, organs, organ systems and finally the living organism. Cells are studied in terms of their processes, structures, functions, interactions with macromolecules and other cells.  

In respiration, the cellular processes convert nutritional energy into chemical energy in the form of ATP for maintenance of internal cell conditions. Biochemical reactions in cellular respiration are separated into different processes of glycolysis, Krebs cycle and electron flow. Understanding cell structure can give further insight to respiration, for example protein structure and synthesis. Cells contain DNA in permutations of base units which are transcripted and translated to produce specific peptides, and polypeptides.

Cell Biochemistry also explores cellular interactions with important macromolecules such as proteins, carbohydrates, and lipids. Enzymes serve as biological catalysts to speed up reactions that break down macromolecules to their constituent units, so cells can use the ATP produced to generate proteins. How cells interact with each other is essential in the functioning of all processes within living organisms. Cell signaling is when a cell sends electrochemical signals to another to produce coordinated responses.  

 

Title Image Credit: Wikimedia Commons

Categories within Cell BioChem

Enzyme, Catalysts and Reactions

Postings: 53

Enzymes are three-dimensional globular proteins, that act to speed up biochemical reactions by lowering activation energy.

Protein Structure and Synthesis

Postings: 29

Protein structure is defined by its primary, secondary, tertiary and quaternary structure. Protein synthesis is a two-step process of transcription and translation.

Carbohydrates

Postings: 5

Carbohydrates are macromolecules that contain carbon (C), oxygen (O) and hydrogen (H).

Cell Signalling

Postings: 12

Cell Signalling is communication between cells using receptor and ligand interactions for tissue repair, growth, transportation of substances and homeostasis.

Open reading frame & deciphering the target protein of interest

Identify the open reading frame in the following DNA sequence, the protein that this gene encodes for, its function, and the source. You can consult the bioinformatics exercise "Project 1: Databases for the Storage and 'Mining' of Genome Sequences" (ATTACHED). The procedure to identify the gene and the protein that it encodes

Respiratory Physiology, Myoglobin & Hemoglobin Structure

Hemoglobin & Transport of O2 & CO2 Include drawings, equations, graphs, etc. where appropriate. 1. Define the following: prosthetic group, fractional saturation, allosterism, cooperativity, Bohr effect, isohydric carriage, respiratory acidosis & alkalosis, metabolic acidosis & alkalosis. Please provide examples. 2.

cell biology questions

1) For each of the following four macromolecules, list their: i) Monomer(s). ii) Functional groups. iii) Linkage type. iv) Primary function. Macromolecules: a) Carbohydrates b) Proteins c) Lipids d) Nucleic acids 2) Show how a peptide bond forms between the two amino acids, glycine and valine. Draw the struc

KM Determination

1.If p-nitrophenyl phosphate had been used as a substrate, would the same Km have been obtained? Explain 2. Elevated blood plasma levels of alkaline phosphatase (hyperphosphatasaemia) are an indication of a number of conditions. Briefly comment on the use of alkaline phosphatase assays as a diagnostic aid for TWO named situa

Chymotrypsin

Chymotrypsin was able to hydrolyse the substrate N-benzoyl-L-tyrosine ethyl ester (BTEE) but not able to hydrolyse the substrate p-toluene sulphonyyl-L-arginine methyl ester (TAME). However the enzyme trypsin was able to hydrolyse both TAME and BTEE substrates, and I was wondering why? And what makes chymotrypsin so much more

Total number of ATP molecules produced from one molecule of maltose

Calculate total number of ATP molecules produced from one molecule of maltose. You will need to consider that first maltose will hydrolyze, then resulting glucose molecules will enter into glycolysis where ATP along with NADH molecules will be produced. Then resulting molecules of pyruvate enter into citric acid cycle and go all

uptake of galactose into red blood cells

I am uncertain how to approach this problem: uptake of galactose into red blood cells was looked at: the data is as follows, galactose concentration mmol/l ^-1 galactose uptake(j)/nmol mg ^-1 protein min ^-1

Multiple choice

I am trying to double check the answers that you get with the ones that I have. 1) Lactose is a disaccharide of glucose and galactose, and its digestion requires the actions of the enzyme lactase If the lactose is taken in as part of the diet, but not digested by lactase, this sugar is then metabolized by bacteria in the

Alcohol dehydrogenase reaction

Consider the reaction catalyzed by alcohol dehydrogenase. (Reaction goes from left to right) CH3CH2OH + NAD+ <-----------> CH3COH + NADH +H+ WHAT IS THE OXIDIZING REAGENT? WHAT IS THE REDUCING AGENT? Please explain.

Ionization State and Cooperative Ligand Binding

1. The active site of lysozyme contains two amino acid residues essential for catalysis: Glu35 and Asp52. The pka values of the carboxyl side chains of these low residues are 5.9 and 4.5 respectively. a) What is the ionization state (protonated or deprotonated) of each residue at pH5.2? What is the pH optimum of lysozyme? b) H

Activity Recovered in Denaturing/Renaturing Types of Insulin

Insulin consists of two peptide chains, a shorter A-chain and a longer B-chain. The two chains are held together with disulfide bonds. Invivo, insulin is processed from a single polypeptide chain called proinsulin by specific protease. Processing involves removal of the C-chain from proinsulin as indicated. A denaturation/renat

Terminal Residue in Alpha Helix

Shown attached is a helical wheel projection of one of the Alpha helices from human hemoglobin. This is an amphipathic helix with one side polar and exposed to solvent and the other side nonpolar and buried. Indicate approximately which side of the helix is likely to be in the solvent exposed and which side is likely to face the

Solve: Octapeptide Protein

You have isolated and purified a a small octapeptide protein and want to determine its primary structure. Deduce the sequence from the following experimental results. A) Complete amino acid analysis, corrected for amino acid hydrolysis loss yielded the following composition (Arg, Glu, Lys, Met, Ser, Thr, Trp, Tyr). B) Reducti

GRE Subject Question - Purification of a Protein

Biochemists generally like to study and characterize proteins as pure substances isolated from their native enviroment. What is the single most important method or procedure that must be availible prior to starting the purification of a protein?

BIOCHEM GRE Subject Question

You have been investigating a membrane protein that appears to have seven 24 residue transmembrane Alpha helices. Assume that each helix is perpendicular to the plane of the membrane and goes exactly from side of the membrane to the other. Also assume that each helix is linked to the next by a loop with a minimun of 12 amino aci

Human Hemoglobin Sample

Normal Human Hemoglobin (HbA) P50 = 26 torr and the hill coefficientis N= 2.8 You have obtained the following oxygen binding curve data on a new sample of human hemoglobin. A) Is this sample normal? (This can be solved by visual inspection) po2 log(po2) Theta theta/1-Theta) Log(theta/1-Theta) 10 1.000 0.0039 0.0039

GRE Subject Question

How many different primary sequences are possible for a pentapeptide made from naturally occurring amino acids? Considering that most proteins are composed of one hundred or more what conclusions can be drawn from the calculation?

Lactate Dehydrogenase and Disulfiram (Antabuse)

Questions 1 - The enzyme loctate dehydrogenase (LDH) is present in all tissues as a catalyst of anaerobic glycolysis. It has 5 isoforms, describe these isoforms and how they can be used in differential diagnostic tests. 2 - Disulfiram (Antabuse) is a drug used in the treatment of alcoholism. What enzyme reaction does this dru

The Enzymes of Glycolysis

What are the various strategies used to regulate glycolysis (do not include glycogen phosphorylase in this question), but include how various inhibitors and activators function, how a highly endergonic reaction is facilitated, and what the roles of isozymes are.

Pathway of Atoms in Fermentation

A "Pulse-chase" experiment using 14C-labeled carbon sources is carried out on a yeast extract maintained under strictly anaerobic conditions to produce ethanol. The experiment consists of incubating a small amount of 14C-labeled substrate (the pulse) with the yeast extract just long enough for each intermediate in the fermentati

Pathway of Atoms in Gluconeogenesis

A liver extract capable of carrying out all the normal metabolic reactions of the liver is briefly incubated in separate experiments with the following 14C-labeled precursors (see attached). Trace the pathway of each precursor through gluconeogenesis. Indicate the location of 14C in all intermediates and in the product, glucose.

Catalytic Function - Optimum pH

The catalytic function of most enzymes is a sensitive function of pH. The attached plot (activity vs pH) of the data will clearly illustrate the degree of this sensitivity. What is the optimum pH for this enzyme?

Picking the Best Inhibitor when Given Km, Kcat and Ki

Here are the following numbers I have calculated; We were given a substrate to plot againist velocity and 3 enzymes to plot as well. From the data: Enzyme A Ki= 2.575 | Kcat = 50 | Km= 3.33 Enzyme B Ki = 10.33 | Kcat = 16.65 | Km = 33.3 Enzyme C Ki= 1.00 | Kcat = 10 | Km = .2 I'm having tr

Artificial Cells

What are artificial cells? How are artificial cells produced? Examples of artificial cells and applications of artificial cell in biochemistry and medicine.

How many grams of alcohol will be produced?

Enzymes in yeast convert sugar (C6H12O6) to alcohol (C2H5OH) according to the following equation: C6H12O6 2 C2H5OH + 2 CO2 If you start with 270 grams of sugar, how many grams of alcohol will be produced?