Week 2 Flashcards
Define covalent bond
Covalent bonds hold atoms together to form molecules.
It is a strong bond and it is hard to break.
You need chemical energy to make bonds and to brake bonds.
Distinguish between polar and non-polar molecules
Non-polar molecule share electrons evenly and they have the same charge on both nuclei.
Polar molecule electrons spend more time near the larger nucleus. H2O and DNA are polar
Describe hydrogen bonds
- Hydrogen bonds have weak charges (+/-) attractions between polar molecules.
- They are easily broken by change in PH or temperature
- They hold water molecules together
- They allow dissolution of polar substances in water
Examples of hydrogen bonds
• Water : - Low temperature = Little
vibration or movement
- High temperature = Lots of
vibration or movement , hydrogen bonds
are broken
• DNA : - The double helix structure of DNA is due to
hydrogen bonds
List the different groups of macromolecules and identify exemples
- Lipids (IE. Fats)
- Carbohydrates (IE. Pasta, bread, rice)
- Nucleic Acids (IE. RNA, DNA)
- Proteins (IE. Meat)
Lipids & Examples
- They are hydrophobic (they do not
dissolve easily in water therefore they
are non-polar) - It is a polymer
- Examples & Roles:
- Triglycerides (fat): Storage of energy, prevent
heat loss, cushioning - Cholesterol & Phospholipid: Form cell membrane
- Steroids: Act as molecular messenger
- Wax: Waterproof coat/Protect against
dehydration
- Triglycerides (fat): Storage of energy, prevent
Carbohydrates (energy & structure) & Explain monomers, dimers and polymers with examples
- Carbohydrates provide calories and
energy - Monomers (1 unit):
IE. Glucose, Fructose, Galactose - Dimers (2 subunits):
IE. Lactose (glucose + galactose)
Sucrose (glucose + fructose) - Polymers (several units):
IE. Animals (glycogen(energy, animals))
Plants (starch (energy): cellulose (structure))
Explain the importance of macromolecules to life
Macromolecules provide structural support, a source of stored fuel, the ability to store and retrieve genetic information, and the ability to speed biochemical reactions.
Describe the structures of nucleic acids and proteins
- Proteins is a molecule made up of polypeptides (polymers) which are chains of amino acids (monomer)
- Nucleic Acids are composed by nucleotides:
A typical nucleotide is made up from a:- Phosphate group
- Sugar group
- Nitrogenous base ( Purine- A, G) (Pyrimidine- C,
T, U)
Describe the functions of nucleic acids and proteins
- The function of proteins are structures, transporting O2, communication, movement, enzymes, defense/immunity, storage, receive signals, etc
- The functions of nucleic acid are storage and expression of genetic information, Heredity(DNA) and protein synthesis(DNA, RNA)
Name what are in Purine and Pyrimidine
- Purine: • A (adenine)
• G (guanine) - Pyrimidine: • C (cytosine)
• T (thymine) (DNA)
• U (uracil) (RNA)
Define mutations and explain consequences
A mutation is a change sequence in our gene creating a new allele. Mutations can result from DNA copying mistakes made during cell division, exposure to radiation, chemicals, viruses, etc.
A harmful mutation may cause genetic disorders or cancer.
Summarize how nucleic acids and proteins are related.
The nucleic acid has the information to make proteins.
Determine which groups of organisms belong to prokaryotes and eukaryotes
- Eukaryotes: Eukarya (plants, animals,
Protist, fungi) - Prokaryotes: Bacteria, Archaea
Distinguish between prokaryotic and eukaryotic cell. Identify similarities and differences.
Similarities:
• They both carry out functions necessary for their survival like adaptation through evolution, growth, reproduction, etc.
• They both contain DNA (packed into chromosome)
• They both have a cell membrane (plasma mem)
• They both have cytoskeleton
• They both have ribosomes
Differences:
• A eukaryotic cell is larger than a prokaryotic cell
• A eukaryotic cell has a membrane-bound nucleus and Prokaryotic cell do not