Biological Molecules Flashcards

Question

What part of an enzyme binds to the substrate and why can it do so?

Answer 1

The active site binds to the substrate because it is specific and complimentary to the substrate.

Answer 2

Lock and key The substrate fits into the enzyme perfectly - like a key into a lock. When the product(s) are formed, they have a different shape so are released. Induced fit The substrate is of a similar shape to the enzyme. Enough of the substrate can fit so the enzyme flexes and becomes complimentary. This puts strain on the bonds in the substrate.

Answer 3

A inhibitor is a molecule which binds to the enzyme and decreases the rate of reaction.

Answer 4

Competitive inhibitors bind to the active site, competing with the substrate to decrease the number of enzyme-substrate complexes. They can be outcompeted by adding more substrate. Non-competitive inhibitors bind to elsewhere on the enzyme, changing the shape of the active site so that it is no longer complimentary to the substrate. They not only decrease but limit the rate of reaction.

Answer 5

pH = -log₁₀(H⁺)

Answer 6

H⁺ = 10⁻ᵖᴴ

Answer 7

``` Nucleotides -- Monomer of DNA -- Phosphate group -- Deoxyribose sugar -- Nitrogenous base -- Join to each other in condensation reactions -- Phosphodiester bonds between the sugar and phosphate -- Forms phosphate-sugar backbone Bases -- Adenine -- Thymine -- Guanine -- Cytasine -- Two hydrogen bonds form between A and T -- Three hydrogen bonds form between G and C Double helix Two strands give DNA more stability ```

Answer 8

``` Similar to DNA Also made of nucleotides Ribose sugar instead of deoxyribose Uracil instead of thymine Single-stranded molecule ```

Answer 9

Conservative - entire double helix conserved, entire new copy made Semi-conservative - each strand is conserved separately and acts as a template for the formation of a new strand Dispersive - original double helix dispersed among the two new double helices

Answer 10

DNA helicase breaks hydrogen bonds between bases Strands separate Free nucleotides are attracted to their complimentary bases DNA polymerase adds the nucleotides to the strands Nucleotides join with each other by undergoing condensation reactions

Answer 11

The relative simplicity of DNA led many scientists to doubt that it carried the genetic code.

Answer 12

Watson and Crick worked at the University of Cambridge to theorise the structure of DNA. Using Chargaff's rule of complimentary base pairing and Rosalind Franklin's X - shaped image of DNA, they were able to model the structure of DNA.

Answer 13

ATP stands for adenosine triphosphate and is formed from ribose, adenine and three phosphate groups. It stores energy in its high energy bonds between the phosphate groups. It is the universal currency of energy exchange in biological systems.

Answer 14

Start with ATP ATP splitting releases energy used for muscle contraction, active transport and biosynthesis Hydrolysis reaction --> ADP + P Formation of ATP requires energy from the oxidation of glucose Condensation reaction --> ATP

Answer 15

``` Metabolic processes Movement (muscle contraction) Active transport Secretion Activation of molecules ```

Answer 16

Water: Is a metabolite in many metabolic reactions, including condensation and hydrolysis reactions Is an important solvent in which metabolic reactions occur Has a relatively high specific heat capacity, buffering changes in temperature Has a relatively large latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation Has strong cohesion between water molecules; this supports columns of water in the tube-like transport cells of plants and produces surface tension where water meets air.

Answer 17

Hydrogen ions The more hydrogen ions the lower the pH Affects hydrogen bonds in enzymes Iron ions Forms part of the haem group (prosphetic group in haemoglobin) Attracts oxygen molecules Sodium ions Co-transport with glucose or amino acids in the small intestine Phosphate ions Provides high energy bonds in ATP Makes up the backbone of DNA Hydrophilic head in phospholipids

Biological Molecules Flashcards

(42 cards)