2.1 Molecules to metabolism Flashcards
What do we mean by organic?
Carbon containing
What do living things contain a lot of? (4)
Hydrogen, oxygen, phosphorous, nitrogen
Why is carbon special?
- It has tendency to form strong covalent bonds
- Valency of 4 so can bond with 4 other atoms - form long chains and complex molecules
- Can form single, double and triple bonds - extremely versatile
- Can form right and chain structures, framework atom
What are all living things composed of? Which 4 main classes of carbon compounds? What do they have in common?
- Carbohydrate, lipids, proteins and nucleic acid
- Each have different structures but they all contain carbon, hydrogen and oxygen
- The differences in structures allows for different purposes
What is carbohydrate characterized by?
their composition
* carbon, hydrogen and oxygen
* hydrogen and oxygen in the ratio of two hydrogen atoms to one oxygen
What are lipids?
- a broad class of molecules that are insoluble in water, including steroids, waves, fatty acids and triglycerides
- are fats if they are solid at room temperature or oils if they are liquid at room temperature
What are proteins composed of?
of one or more chains of amino acids.
* the amino acids contain the element carbon, hydrogen, oxygen and nitrogen
* but two of 20 amino acids also contain sulphur
What are nucleic acids?
chains of subunites caled nucleotides
contain carbon, hydrogen, oxygen, nitrogen and phosphorous
there are two types: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)
What is metabolism? What is metabolic rate?
The totality of chemical reactions that occur in an organism
The rate at which these chemical reactions take place.
What is the difference between metabolism, anabolism and catabolism?
Anabolism builds complex molecules from simpler ones, while catabolism breaks large molecules into smaller ones
Metabolism is the totality of chemical reactions
What are some processes of anabolism?
- Protein synthesis using ribosomes
- DNA synthesis during replication
- photosynthesis, including production of glucose from carbon dioxide and water
- synthesis of complex carbohydrates incuding starch, cellulose and glycogen
What are some processes of catabolism?
- digestion of food in mouth, stomach and small intestine
- cell respiration in which glucose or lipids are oxidized to carbon dioxide and water
- digestion of complex carbon compounds in dead organic matter by decomposers
Why do elements bond? How? What are the two types?
To achieve stability by gaining a full outer ring of electrons.
Ionic: transfer of electron, usually weaker bonds, metal to non-metal
Covalent: sharing of electrons, stronger bond, between non-metals
What are hydrogen bonds? How strong are they? Where are they present in? How can they be broken?
Hydrogen bonds are the interactions that are formed between a slightly positive end of one molecule and a slightly negative end of an adjacent molecule.
- There a weak individually but strong together
- is present in DNA, water, cellulose, proteins
- can easily be broken by heat and pH changes
How are dipoles created? What are the molecules with dipoles called?
- Dipoles are created when there’s a slight charge distribution and molecules.
- Molecules with dipoles are called polar
What are monomers and polymers?
What is the monomer and polymer of these biological molecules: carbohydrates, proteins, nucleic acid?
Monomers are single small molecule which are joined together to form polymers.
Biological molecule -> monomer -> polymer
- Carbohydrate -> monosaccharide -> polysaccharide
- Proteins -> amino acids -> polypeptide
- Nucleic acids -> nucleotide -> nucleic acid (DNA, RNA)
What is condensation and hydrolysis?
Condensation
1) Builds monomers into polymers
2) releases water
3) forms a new covalent bond
Hydrolysis
1) Breaks polymers into monomers
2) requires water
3) breaks covalent bonds
Name three chemicals in living things which contain many carbon atoms
proteins, lipids, nucleic acids, and carbohydrates.
What is a macromolecule?
A molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.
What are 3 examples of hydrolysis reactions in biological cells?
1) polypeptides + water -> dipeptide or amino acids
2) polysaccharides + water -> disaccharide or monosaccharide
3) glycerides + water -> fatty acids + glycerol
What is urea?
a nitrogen-containing compounds with a relatively simple molecular structure
When is urea produed?
when there is an excess of amino acids in the body, as a means of excreting the nitrogen from the amino acids
Where is urea produced?
in the liver from a cycle of reactions, catalysed by enzymes
Where is urea produced?
in the liver from a cycle of reactions, catalysed by enzymes
What is the cycle of reactions occuring in liver cells that is used to synthesize urea?
ornithine cycle
Draw the ornithine cycle
What is the equation for producing urea in the body in words?
ammonia + carbon dioxide -> ammonium carbanate -> urea + water
