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
What are conjugated proteins?
Chains of amino acids conjugated with other groups. Proteins joined with other molecule.
What is a proteome?
Complete array of proteins produced by a single cell or organism in a particular environment.
What is proteomics?
Study of proteome.
How many parts does a nucleotide have and what are they?
- Sugar
- Phosphate
- Nitrogen base
⚪️-(phosphate)
\/(sugar)_ (nitrogen base)
\ _____ /
What are the sugar and phosphate parts of DNA held together by?
What are the bases held together by?
Strong covalent bonds.
Weaker hydrogen bonds.
What are the 4 nitrogen bases of DNA?
Thymine, Adenine, Cytosine and Guanine
Which nitrogen base of DNA is different for RNA?
Thymine is replaced by Uracil.
What are the 3 types of RNA and what did they do?
- MESSENGER RNA- (mRNA) copies code in DNA-ribosome
- TRANSFER RNA-(tRNA) molecule that carry amino acids to ribosomes to construct proteins
- Ribosomal RNA- (rRNA) nucleotides are made in rRNA; forms part of ribosome structure
Where is RNA found?
Cytoplasm of the cell and nucleus.
