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nucleic acids and proteins
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∙ 12y ago
Wiki User
∙ 13y agowater
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What keeps DNA together?
DNA is kept together by hydrogen bonds. The bonds connect the bases together and gives DNA its double helix shape.
Are enzymes still functional after losing their shape?
enzymes are still functional after losing their shape as they depend onn their shape
When a substrate molecule comes in contact with the active site of an enzyme what happens?
Enzymes speed up the rate of reaction by lowering activation energy needed to begin a reaction. They are globular (spherical) proteins and are highly specific, with a shape maintained by hydrogen and ionic bonds, and hydrophobic interactions along the polypeptide chain. So, a substrate with a specific shape that exactly fits the shape of the enzyme's active site bonds to the site with noncovalent bonds, a mixture of ionic and hydrogen bonds. The enzyme will then increase the likelihood of bonding in the substrate molecule or conversely will weaken, stress and finally break bonds so that atoms can be rearranged into a product. An enzyme is NOT changed in a reaction. : )
Why is it important for these bonds to be weak?
If by "weak chemical bonds" you are referring to intermolecular attractions, which are weaker than chemical bonds, but still sufficiently strong enough to hold certain molecules together, then they are very important. DNA, for instance, forms itself into a double-helix shape, the structure of which is held together by the attraction between molecules. This attraction is not a bond (ionic or covalent); but it is an electrostatic binding, which forms a framework for this vital molecule.
What are enzymes and what are they made of?
Enzymes are biological catalysts. This means they break down substances without being changed themselves. This is why they can be used over and over again. Enzymes are made from amino acids joined together by different bonds, one of the type of bonds being hydrogen bonds. As enzymes have hydrogen bonds it means they are sensitive to pH and temperature. A temperature too low will mean that the molecules (substrate) which should fit to an area on the enzyme called the active site cannot do so as hydrogen bonds are stronger in colder conditions. (Enzymes change slightly as the substrate fits on to it) This would mean that the enzyme is less able to change shape slightly because the stronger hydrogen bonds make the enzyme less flexible. Temperatures which are too high for the enzyme (if they exceed the perfect temperature, called the optimum temperature, of the enzyme) denature the enzymes, meaning that they are unable to catalyse chemical reactions, this is due to the high temperature causing the hydrogen bonds which bond the amino acids together to beak, causing the enzymes active site to change shape, meaning that the substrate can no longer fit into the active site meaning that the rate of reaction of the chemical reaction is lower. There is a point when the hydrogen bonds, once broken, are no longer able to re-bond, meaning the enzyme could never "re-nature". This is very bad if the chemical reaction is necessary. If the pH which the enzyme is exposed to is not its optimum the rate of reaction will be slower as the pH changes the molecular shape of the enzyme, and can have an effect on the intermolecular forces of the Hydrogen bonds (it can weaken or strengthen them)
A denatured protein or DNA molecules has lost what?
It has lost its active 3D structure and therefore it is not functional anymore.
What forces and bonds maintain the three dimensional folded shape of a protein molecule?
hydrogen bonds
What bonds usually hold large molecules in their 3-dimensional shape teriary structure?
Hydrogen Bonds
What type of bonding is responsible for maintaining the shape of the tRNA molecule?
hydrogen bonding between base pairs
Which bonds often bind different parts of a molecule into a specific three dimensional shape?
Hydrogen
What keeps DNA together?
DNA is kept together by hydrogen bonds. The bonds connect the bases together and gives DNA its double helix shape.
What type of bonding is found in DNA?
DNA ( Deoxyribo Nucleic Acid) is held together by a hydrogen bond in between the two bases connecting the two backbones that make the "twisted ladder" shape. The backbones are held together by sugars and phosphates. They are usually called sugar-phosphate backbones.
The stability of the three-dimensional shape of many large molecules is dependent on?
The stability of the three-dimensional shape of many large molecules is dependent on Hydrogen Bonds.
What is the term used for a change in a protein's three dimensional shape or confirmation due to disruption oh hydrogen bonds disulfide bridges or ionic bonds?
The change in a proteins' three dimensional shape or conformation is called denaturation.
Why do abnormal elevated temperatures degrade proteins?
The heat breaks the hydrogen bonds between the amino acids, and the shape is changed.
Are enzymes still functional after losing their shape?
enzymes are still functional after losing their shape as they depend onn their shape
Shape of hydrogen?
Hydrogen is a gas and so has no shape.
