Module 1 Flashcards
Characteristics that define life
- Cellular organization
- Reproduction
- Metabolism
- Homeostatic
- Hereditary
- Response to stimuli
- Growth
- Adaptation (evolution)
Scale of life
Ranging from biological molecules in nm to single cells in um to multicellular with a broad range.
Requirements of natural selection
- Variation in a population
- Inheritance of hereditary variation
- Some form of selection filter
- Time
Macromolecules
Mostly formed of polymerization of building blocks:
- Nucleic acids (RNA and DNA)
- Carbohydrates (polysaccharides)
- Lipids (fats)
- Proteins (polypeptides)
Building blocks
The basis building blocks of larger molecules, often with variations:
- Amino acid (peptide)
- Nucleobases (for nucleic acids)
- Simple Carbs (sugars)
- Fatty acids
- Hydrocarbon rings (hex and pent)
Supramolecular assemblies
Assembled of macromolecules and building blocks to serve specific functions:
- Membranes
- Ribosomes
- Chromatin
Mono saccharide
Simple sugar which can be assembled into macromolecules, either hexosaccharide (leading to higher order carbs) or pentosaccharide (leading to larger molecules, such as nucleic acids) depending on number of carbons
Disaccharide
Simple sugar, composed of 2 monosaccharides which are easily broken down for energy
Oligosaccharide
3-10 monosaccharides stuck together
Polysaccharide
10 or more mono saccharides
Starch
Amylose and amylopectin, plant exclusive production and entirely glucose composed
Glycogen
Animal only, glucose monomer composition, good store of energy
Cellulose
Fiber of plants formed of glucose in an H-bond regular pattern
Functions of Carbohydrates
Recognition - for cell communication and identification
Energy - both for storage and use (via enzyme breakdown)
Structure - Cellulose provides plants structure and humans their dietary fibre
Nucleotide
Phosphate group attached to ribose sugar attached to nucleic base. The building block for nucleotides
RNA
Single stranded helix, bases point to center
DNA
Double helix makes knots, bases matched, but pointing to centre
Phospholipid
Hydrophilic head of glycerol with hydrophobic tails of fatty acids. Component of cell membranes
Cholesterol
Same as phospholipid, but shorter tail, component of membrane. Steroidal and can be turned to test/estrogen
Functions of Lipids
Structure - such as in cell membranes
Regulation - cholesterol can be used to make hormones
Energy - ‘fat’ aka triacylglycerol which has glycerol column ester bound to carbohydrates
Peripheral protein
Not embedded in lipid bilayer, loosely bound to membrane surface, often attached to an exposed integral protein
Cytoskeleton
Structure that helps maintain organization and mechanical support for cell function. Composed of interlinking protein filaments and spans entire cytoplasm
Functions of integral proteins
Transport - either active or passive provides hydrophilic channel for selected solutes
Enzyme - involved in processing compounds for metabolism
Signal transduction - May have a binding site for a signaling molecule
Recognition - Glycoproteins can function as ID tags that match receptors
Intercellular joining - Membrane proteins may hook together to form junctions
Structure - Can provide point of attachment between cytoskeleton and ECM
Selective permeability
Allows some substance to pass through more easily than others