0
Biochemistry
Biochemistry is the study of the structure, composition and chemical processes in all living organisms. It covers the structures and functions of various cellular components, including proteins, carbohydrates, nucleic acids, lipids, and other biomolecules.
8,065 Questions
Focus knobs are adjustable controls on optical devices such as microscopes or cameras that allow the user to refine the focus of the image, making it clearer and sharper by adjusting the position of the lens. By turning the focus knob, the user can bring objects into sharp focus by moving the lens closer or farther away.
How do you determine shape and size of biomolecule in solution?
Size is easy. There are a number of techniques, some more accurate than others:
Mass spectroscopy - very accurate (to within ~0.1%). Requires a solution of about 1mg/ml.
Gel filtration chromatography - not particularly accurate (to within ~10%) and also influenced by shape.
SDS-PAGE - very crude estimation for proteins (commonly greater than 10% error) but based solely on molecular weight as molecules are denatured and given uniform charge.
Agarose gel - rough estimation for DNA.
Sequencing - protein/DNA sequencing would allow calculation of an approximate size, but it is much easier to use mass spectroscopy.
Analytical centrifugation - accurate but takes a very long time so rarely used.
A combination of the above methods can provide information on shape too. A typical early experiment on a protein, for example, might include both SDS-PAGE and gel filtration. Since one depends on size and shape, while the other is only size, one can determine its oligomer state (whether or not it binds to itself in solution) if it is known to be globular, or it can indicate if a protein is not roughly spherical (most are).
Shape is more complex:
As discussed above some basic information on shape (linear or globular and oligomerization) can be gained from the simple methods listed above. Further information can be gained through X-Ray crystallography, cryoelectron microscopy or COESY/NOESY 3D NMR spectroscopy. One of these techniques is usually able to give a reasonable high resolution three dimensional structure of a protein, but it is a time consuming and costly process.
For the very small biomolecules, mass spectroscopy and NMR spectroscopy (but not NOESY/COESY) are usually sufficient for determining both size and shape, as shape can be predicted using known bond length and angle constraints to a reasonable degree of accuracy.
Does bacillus subtilis have a capsule?
Yes, Bacillus subtilis is known to produce a polysaccharide capsule that surrounds the cell. This capsule is involved in protecting the bacteria from desiccation, phagocytosis, and other environmental stresses.
What is the attractive force between like particles is called?
The attractive force between like particles is called cohesion. It is the force that holds similar particles together within a substance.
What is the name of the hormones that have a pronounced effect in a localized area?
The name of the hormones that have a pronounced effect in a localized area are paracrine hormones. These hormones act on nearby cells within the same tissue or organ where they are released, rather than traveling through the bloodstream to distant target cells.
Why do living cells need catalytic enzymes?
First of all living cells use catalysts (more specifically - enzymes), because without them it would need an extremely long period of time for all of the biochemical reactions to finish. Of course, enzymes are not the only thing which may change the speed of the reaction - if the environmental conditions (temperature, pH, pressure and others) are changed the reactions also may start to run faster. But the change of these conditions may kill the organisms or reduce their fitness. For instance, if the temperature becomes higher - yes the reactions would start to run faster. But the nucleic acids and the proteins of the organism are going to denature (their normal folding processes are going to be disrupted), so this eventually would kill or damage the organism (that is what happens when a living tissue is burnt).
How does collagen helix differs from alpha helix?
A collagen helix is less compact (because it goes into triple helices), and it is a left-handed helix. An alpha helix is more compact and hence requires more rotation of bonds to form (hence proline is not very common...has an imidazole ring). It is a right-handed helix, and goes into double helices instead.
How does photosynthesis relate to your daily lives?
Photosynthesis is vital for our daily lives as it is the process by which plants, algae, and some bacteria convert sunlight, water, and carbon dioxide into oxygen and glucose. The oxygen released during photosynthesis is essential for us to breathe, while the glucose provides energy for all living organisms. This process is crucial in maintaining the balance of gases in the atmosphere and providing food for the ecosystem.
What is the first step in DNA synthesis?
The first step in DNA synthesis is the unwinding of the double-stranded DNA molecule by an enzyme called helicase. This process separates the two strands of DNA, creating a replication fork where the synthesis of new DNA strands can occur.
What carbohydates are monosaccharides?
Some examples are:
- D-aldoses: D-Erythrose, D-Threose, D-Ribose, D-Altrose, D-Glucose, D-Mannose, D-Gulose, D-Idose, D-Galacotose, D. Talose, among others.
- D-ketoses: D-Erythrulose, D-Ribulose, D-Xylulose, D-Psicose, D-Fructose, D-Sorbose, D-Tagatose, among others.
What is an example of atp synthase?
ATP synthase is a protein complex found in the inner membrane of mitochondria and the thylakoid membrane of chloroplasts. It helps generate ATP by using a proton gradient established across the membrane to drive the synthesis of ATP from ADP and inorganic phosphate.
Which process uses chloroplasts in eukaryotes?
Photosynthesis is the process that uses chloroplasts in eukaryotes. Chloroplasts are membrane-bound organelles that contain chlorophyll, enabling them to capture sunlight and convert it into chemical energy to produce sugars from carbon dioxide and water.
No, iron is a mineral and not an amino acid. Iron is essential for many biological processes in the body, such as oxygen transport and energy production. Amino acids, on the other hand, are the building blocks of proteins.
Proteins are produced as polymer of amino acid chains. They gain secondary structure elements such as alpha helix, beta sheet during folding and for their three dimensional structure. Some proteins such as Hemoglobin make quaternary structure where they form the final structure with four different subunits of two different proteins interacting each other.
Amino acids that cannot be produced by the body?
There are nine essential amino acids: histidine (essential for children), isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These amino acids must be supplied by food; the body cannot make them.
What is the scientific name for cell division?
Mitosis is a cell division which takes place in normal body cells. Mitosis produces daughter cells which are identical to the original cell. Body cells all have the same genetic information due to Mitosis. Body cells that are produced during Mitosis all need the same genetic information so that they can do the same job as the original cell. Before the cell can divide it must make new copies of the chromosomes in its nucleus. This allows for cells that are produced to have identical genetic information. Two daughter cells are formed. Mitosis is asexual cell division.
Which illegal steroid is 2a 17a di methyl etiocholan 3 one 17b ol most similar to?
2a 17a di methyl etiocholan 3 one 17b ol is structurally similar to the illegal steroid known as Superdrol (Methasterone). Both compounds are synthetic derivatives of testosterone and have powerful anabolic effects, making them popular choices among bodybuilders and athletes looking to boost muscle growth and performance.
Erythropoietin is a hormone that stimulates the production of red blood cells in the bone marrow. It is primarily produced by the kidneys in response to low oxygen levels in the blood. Erythropoietin plays a key role in maintaining the body's oxygen level and overall health.
Why are infant formulas often contain mixtures of dextrins and maltose rather than starch?
Infant formulas contain mixtures of dextrins and maltose because they are easier for infants to digest compared to starch. Dextrins and maltose are simpler carbohydrates that are closer in structure to human milk, making them gentler on a baby's developing digestive system. Additionally, dextrins and maltose provide a quicker source of energy for infants.
What is the most toxic fat soluble vitamin?
Vitamin A has the highest toxicity potential of the Fat soluble vitamins as too much can cause weakened bones and increased fractures. The male and female daily required intakes is 900 and 700 mcg respectively, whereas the upper tolerable limit is around 3,000 mcg.
Different between oxidative phosphorylation and substrate level phosphorylation?
Substrate-level phosphorylation occurs during Glycolysis and the Kreb's Cycle and involves the physical addition of a free phosphate to ADP to form ATP. Oxidative phosphorylation, on the other hand, takes place along the electron transport chain, where ATP is synthesized indirectly from the creation of a proton gradient and the movement of these protons back accross the membrane through the protein channel, ATP synthase. As the protons pass through, ATP is created.
What part of the body stores water solubles and fat solubles?
Water-soluble vitamins are stored mainly in the liver and fat-soluble vitamins are stored in the body's fatty tissues.
How fast or rate is the catalase enzyme?
The catalase enzyme typically has a high turnover rate, meaning it can catalyze the breakdown of hydrogen peroxide molecules quickly. It can convert millions of molecules of hydrogen peroxide into water and oxygen per second. The rate of catalase activity can be affected by factors like substrate concentration, temperature, and pH.
