Important things possibly on the test Flashcards
Explain phosphodiester bonds
Phosphodiester bonds are covalent bonds that link nucleotides together in nucleic acids like DNA and RNA. they form when the phosphate group of one nucleotide bonds with the hydroxyl group on the 3’ carbon of the sugar of another nucleotide, releasing a water molecule in the process. This creates a sugar-phosphate backbone, giving the nucleic acid strand direction (5’ to 3’), which is important for genetic information storage.
Explain buffers(use an example ie bicarbonate carbonic acid buffer)
Buffers are substances that maintain a stable pH in a solution, such as the bicarbonate-carbonic acid buffer system, which helps regulate blood pH by allowing carbonic acid to dissociate and release hydrogen ions when the pH drops, or by combining bicarbonate with excess hydrogen ions when the pH rises, thus preventing drastic changes in acidity.
Identify certain functional groups
- Hydroxyl Group (-OH)
Structure: R-OH, alcohols - Carbonyl Group (C=O)
Structure: R-C(=O)-R’, aldehydes and ketones - Carboxyl Group (-COOH)
Structure: R-COOH, organic acids - Amino Group (-NH2)
Structure R-NH2, amino acids - Phosphate Group (-PO4)
Structure: R-OPO3, nucleotides, nucleic acids - Sulfhydryl Group (-SH)
Structure: R-SH, other molecules
Explain the properties of water and an example of its use in real life
Cohesion: allows water to form droplets and contributes to its surface tension
- in plants, cohesion helps transport water from the roots to the leaves through capillary action in the xylem.
Effect: High surface tension
Adhesion: allows water to “stick” to surfaces
- Crucial in capillary action, enabling water to move upward in narrow pipes, such as in the roots and stems of plants.
High Specific Heat Capacity: water can absorb amount of heat before its temp changes, helps regulate temp
- oceans & large bodies of water can moderate coastal climates, preventing extreme temperature fluctuations and creating stable environments for marine life.
High Specific Heat of Vaporization: water requires some energy to change from liquid to vapour.
- essential for thermoregulation in humans and other animals. when sweat evaporates from the skin, it remove excess heat, helping to cool the body
High density at 4°C: water is most dense at 4°C. as water cools below this temp, it expands and becomes less dense, which is why ice floats on water!
- vital for aquatic life; during winter, ice forms on the surface of lakes, insulating the water below and allowing organisms to survive in the liquid water beneath
Describe how hemoglobin structure relates to function
The structure of hemoglobin, consisting of 4 polypeptide chains and heme groups that can bind oxygen, enables cooperative binding and allosteric regulation, allowing it to efficiently pick up oxygen in the lungs and release it in tissues where it’s needed, while also responding to changes in pH and CO2 levels
Know how to form the 3 disaccharides (sucrose, maltose, lactose), how to connect amino acids, how to form triglycerides
Cohesion
Characteristic: Water Clings
Ex: water molecules from hydrogen bonds with one another
Effect: High surface tension
Adhesion
Ex: water molecules from hydrogen bonds with other polar materials
Effect: Capillary action causes water to creep up a narrow glass tube and paper (transpiration)
High specific heat capacity
Characteristic: Water absorbs a lot of heat
Ex: H bonding causes water to absorb amount of heat before temp increases, causes it too lose large amount of heat before temp decreases
Effect: temperature moderation. helps organisms
High specific heat of vaporization
Ex: H bonding causes liquid water to absorb large amount of heat to become vapour (gas)
Effect: evaporative cooling. allows organisms to dissipate body heat by evaporation from skin and tongue.
Highest denisty at 4°C
Characteristic: solid water is less dence than liquid water
Ex: below 0°C, water molecules form a crystalline lattice. H-bonds spread apart, low density
Effect: ice floats on liquid water allowing for aquatic life in winter. ice on water insualates the water below
