Paper 2 Flashcards
Bonds in Carbohydrate
Glycosidic Bonds
Bonds in lipids
Ester bonds
Bonds found in proteins
Peptide bond
Bonds found in nucleic acid
Phosphodiester Bond
Alpha Glucose
The hydroxyl (-OH) attached to the first carbon (C1) is positioned below the plane
Beta Glucose
The hydroxyl (-OH) group attached to the first carbon (C1) is positioned above the plane of the ring.
Biological Roles of a and b
Alpha Glucose Polymers (Starch, Glycogen): Primarily function as energy storage molecules in plants (starch) and animals (glycogen).
Beta Glucose Polymer (Cellulose): Primarily functions as a structural component in the cell walls of plants and some algae. It is the most abundant organic molecule on Earth.
Structural features of amino acids
—Contains a central carbon atom bonded to four different groups: an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (-H), and a variable R group.
—Look for the presence of both an amino group and a carboxyl group attached to the same central carbon.
Structural features of phospholipids
-Has a glycerol backbone (often appearing as a 3-carbon structure).
-Features two long, nonpolar fatty acid “tails”.
-Contains a phosphate group attached to the glycerol.
-Usually shows a polar “head group” connected to the phosphate.
Structural features of sucrose
-Is a disaccharide (made of two sugar rings).
-Composed of one glucose ring and one fructose ring linked together.
-The linkage between the two rings involves carbon 1 of glucose and carbon 2 of fructose.
Structural features of Fatty Acid Chain
-Appears as a long chain of carbon atoms.
-The chain is mostly made up of carbon-hydrogen bonds.
-One end of the chain will have a carboxyl group (-COOH).
Structural features of starch
-Is a polysaccharide made of many connected sugar units.
-The individual sugar units are alpha glucose rings.
-The glucose rings are linked primarily by alpha (α) 1-4 glycosidic bonds.
-May show branching points with alpha (α) 1-6 glycosidic bonds
Structural features of cellulose
-Is a polysaccharide made of many connected sugar units.
-The individual sugar units are beta glucose rings.
-The glucose rings are linked by beta (β) 1-4 glycosidic bonds.
-The diagram will show alternating glucose rings flipped relative to each other due to the beta linkage.
Describe interphase
•This is the preparatory phase, making up about 90% of the cell cycle.
•The cell grows and carries out normal metabolic functions.
•DNA replication occurs in the S phase, resulting in duplicated chromosomes (sister chromatids).
•The cell prepares for mitosis in the G2 phase by synthesizing necessary proteins.
•Chromosomes are not yet visible and appear as diffuse chromatin.
Describe Prohase
•Chromosomes condense and become visible under a light microscope.
•The nucleolus disappears.
•The mitotic spindle begins to form in the cytoplasm.
•In animal cells, centrosomes move to opposite poles of the cell.
•The nuclear envelope starts to break down in late prophase.
Describe Metaphase
•The duplicated chromosomes align at the metaphase plate (the equator of the cell).
•The centrosomes are now at opposite poles of the cell.
•Each sister chromatid is attached to spindle fibers originating from opposite poles.
Describe anaphase
•Sister chromatids separate at the centromeres.
•The now individual chromosomes move towards opposite poles of the cell, pulled by the shortening kinetochore spindle fibers.
•The cell elongates as the non-kinetochore spindle fibers lengthen.
Describe Telophase
•Chromosomes arrive at opposite poles and begin to decondense (unwind).
•Nuclear envelopes begin to form around each set of chromosomes.
•The mitotic spindle disassembles.
•The nucleolus reappears in each new nucleus.
•Cytokinesis (division of the cytoplasm) typically occurs concurrently with telophase, resulting in two genetically identical daughter cells.
Describe Vmax
Definition: Vmax represents the maximum rate at which an enzyme can catalyze a reaction when it is fully saturated with substrate.
Concept: Imagine a situation where you keep increasing the concentration of the substrate. The reaction rate will also increase, but it will eventually plateau. This plateau represents Vmax. At this point, every active site on every enzyme molecule is occupied by a substrate molecule, and the enzyme is working as fast as it possibly can.
Dependence: Vmax is directly proportional to the enzyme concentration. If you double the amount of enzyme, you will double the Vmax (assuming substrate is not limiting).
Describe Km
Definition: Km is the substrate concentration at which the reaction rate is half of Vmax (Vmax/2).
Concept: Km provides a measure of the affinity of the enzyme for its substrate.
Interpretation:
Low Km: A low Km value indicates that the enzyme has a high affinity for the substrate. This means that the enzyme can achieve half of its maximum velocity at a relatively low substrate concentration. The enzyme binds its substrate tightly.
High Km: A high Km value indicates that the enzyme has a low affinity for the substrate. This means that a higher substrate concentration is required to reach half of the maximum velocity. The enzyme binds its substrate weakly.
Respiratory Adaptations (High Altitude)
-Increased Ventilation (higher breathing rate and depth)
-Larger Lung Capacity
Circulatory Adaptations: Increased Oxygen Carry Capacity
-Increased RBC Production
-Increased Hemoglobin Concentration
Measles
Pathogen: Measles Virus
Mode of Transmission: Airborne (respiratory droplets), direct contact with infected person’s secretions.
Tuberculosis
Pathogen: Mycobacterium tuberculosis (bacterium)
Mode of Transmission: Airborne (when infected individuals cough, sneeze, speak, or sing).
