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
What are the different organelles found in both cells and explain their functions
- Cell membrane:
• They are the interface between the inside and the outside of the cell
• It consists of a phospholipid bilayer with embedded proteins
• It is protein that control transport substances - Cytoskeleton:
• They are consisted of chains of protein fibers
• They provide structure to cells, facilitate transport of materials and cellular movement - Ribosomes:
• It is a complex structure made of proteins and RNA molecules
• They are responsible for synthesis of proteins
• They are found within the cytoplasm - Chromosomes:
• Chromosomes are DNA that are packed
• In prokaryotes: they are found in the nucleoid
• In eukaryotes: they are found in the nucleus
Identify benefits of compartmentalization in eukaryotic cells
- The compartments are referred to as membrane-bound organelles
The different membrane-bound organelles:
- Nucleus: control center that contains DNA
- Lysosome: Breaks down unwanted cells/materials/bacterias/viruses
- Endoplasmic Reticulum (ER): modify proteins and synthesize lipid
- Mitochondrion: Power house it makes energy(ATP)
- Golgi apparatus: Package/Sort proteins and lipid
- Chloroplast(in plants): Responsible for photosynthesis
- Ribosomes: Synthesis/Make proteins
Explain the purpose of endomembrane system and what it includes
- Includes: • Nuclear membrane
• Endoplasmic reticulum
(Smooth and Rough)
• Golgi apparatus
• Lysosomes
• Vesicles
• Vacuoles - Endomembrane system divide the eukaryotic cell into functional and structural compartments
- All compartments work together to modify, package, and transport lipids and proteins
Explain what is unique about mitochondria and chloroplasts and Identify how these organelles contribute to the function of eukaryotic cells
- What is unique about them is that they contain their own DNA
- Mitochondrion: It converts chemical energy (nutriments (eg. Glucose) —> ATP (energy source for cellular activities)
It uses O2 - Chloroplast: It converts light energy(sun) to chemical energy(sugar)
It is found in plants
Describe the endosymbiotic theory and identify supporting evidence
- Start with two independent cells
- The larger cell engulfs the smaller cell
- The smaller cell now lives inside the larger cell
- Both cells benefit from arrangment
- The smaller(internal) cell can still divide
- Smaller cells are passed on as the larger cell
divides
The evidence is that Mitochondria and Chloroplast have a double membrane (the inner is the smaller cell and the exterior is the larger cell)
