Chapter One: Chemical Nature Of Cells Flashcards
What is an atom?
Smallest possible particle of matter.
What is an element?
A group of atoms at a given time.
What is a molecule?
Two or more atoms bonded together.
E.g. Oxygen-O2; Water-H2O
What is a compound?
Mixture of two or more different types of atoms bonded.
E.g. Glucose-C6H12O6
What is an ion?
An atom with a charge (positive or negative).
It can be charged by losing or gaining electrons.
What is a bond?
An energy that joins atoms together.
What are the physical properties of water?
- Greater because of hydrogen bonding
- Cells become rigid
- Hydrogen biding enabled water to creep up capillary tubes in plants
- Essential because it’s a good solvent, neutral
- Water content falling low can cause varied temperature an kill cell
- When frozen it takes up more space
What are the 4 main Bio Macromolecules? What are they made from?
- Carbohydrates (e.g. Carbon, hydrogen, oxygen)
Monomers of simple sugars e.g. Glucose
C,H,O (O must be around half of H) - Lipids (e.g Waxes, phospholipids and triglycerides)
Monomers of fatty acids and glycerol
C,H,O - Protein (e.g. Enzymes, hormones, antibodies and haemoglobin)
Monomers of amino acids
C,H,O,N*,(P,S) - Nucleic acids (e.g. DNA and RNA)
Monomers of nucleotides
C,H,O,N,P
What is hydrolysis?
A reaction in which a molecule of water is used in the splitting of another molecule.
What is a condensation reaction?
2 monosaccharides Are joined with the release of a water molecule to form a disaccharide.
Examples of monosaccharides, disaccharides, and polysaccharides.
Mono (simple sugar molecule)- glucose, fructose
Di (2 monosaccharides)- lactose, sucrose
Poly (many monosaccharides)- cellulose, starch, glycogen
What are the 4 Levels of protein structure?
- PRIMARY- specific sequence of amino acids
- SECONDARY- regular folding of the amino acid chain (polypeptide); alpha helix, beta pleated, random coil; can be several folding patterns
- TERTIARY- irregular folding of entire polypeptide chain into a specific shape. Secondary structure is maintained whilst folding.
- QUATERNARY (not all proteins have 4th structure)- two or more polypeptide chains joined to make a protein.
What happens when enzymes are heated?
The bonds break and they lose their shape- ‘denature’
What are fibrous proteins?
- Polypeptide form long chains (combine alpha helixes and beta sheets) running parallel to each other with little or no tertiary structure
- Chains are linked by disulphides cross bridges-making the proteins very stable and strong
- Relatively insoluble in water
- High tensile strength which gives them structural and supporting functions
E.g. Collagen in connective tissue, myosin in muscle
What are globular proteins?
- Sphere/Globe shape
- More numerous and complex the. Fibrous proteins
- Molecule forms a coil shape
- Hydrophobic groups point into centre of molecule away from water
- Only hydrophilic groups are exposed outside the molecule so globular proteins are soluble in water
- Consist of alpha helix and/or beta sheets folded upon themselves, therefore more compact.
- Very sensitive to temp and pH changes due to weaker cross-linking in chains. Slight changes can disrupt these cross links
E.g. Enzymes, many food proteins
