IBDP Biology Summative Year 1 - November

Topics Included: (Water, Nucleic Acids, Origins of cells, Cell structure, Viruses, Carbohydrates and lipids, Proteins, Membranes and membrane transport, Organelles and compartmentalization, Cell specialization)

What is polarity and how is water a polar molecule?

Water is a molecule in which the charges are unevenly distributed, the oxygen has a more negative charge and the hydrogen has a more positive charge.

How does water's polarity influence its 4 properties as a solvent?

1. Water molecules perform cohesion due to attraction between adjacent molecules.

2. Water molecules perform adhesion due to its ability of London dispersion forces, which induces a dipole in the molecules of the surface.

3. Because of the high number of hydrogen bonds, water molecules display a unique thermal property of absorbing a lot of energy without heating up a lot.

4. Water molecules also act as a good solvent due to its polarity being useful to disassociate solute molecules into ions.

What are 3 applications of water's properties

1. Water's polarity helps it act as a good transport medium for soluble substances like salt in blood.

2. Sweat tends to act as a coolant due to the water's thermal ability to absorb lot of energy.

3. Water is a good medium for metabolic reactions (it absorbs excess heat in exothermic reactions)

What is the nucleic acid monomer

Nucleotide (in both RNA and DNA)

General structural formula: Phosphate, sugar and base

What is a prokaryotic cell?

A cell without a well-defined nucleus, consisting of no membrane-bound organelles

What are the 4 things a Prokaryote does not have?

Mitochondria, Endoplasmic Reticulum, Golgi Apparatus, Nucleus

What is the cell envelope composed of?

capsule, cell membrane, and cell wall.

What is the role of the capsule?

Capsule: Protection from pathogens and adhesion to surfaces

What is the role of the cell membrane?

Cell Membrane: Transports nutrients, Eliminates waste, Maintains constant and organized state.

What is the role of the cell wall?

supports and protects the cell

What does the inside of a prokaryotic cell have?

70S Ribosomes, nucleic region and cytoplasm.

What is the role of ribosomes?

protein synthesis

What is the nucleoid region

The region in a prokaryotic cell consisting of a concentrated mass of DNA.

What is the role of plasmids

Carry genes for antibiotic resistance, toxins, capsules, and fimbriae

What are pili?

Protein filaments that help bacterial cells attach to surfaces and to one another.

What are flagella?

tail-like organelle used by prokaryotes, and some eukaryotes for locomotion

What do prokaryotes and eukaryotes have in common?

ribosomes, plasma membrane, cytoplasm

Prokaryotes vs. Eukaryotes

- Prokaryotes have no nucleus
- Prokaryotes do not have other membrane bound organelles (Mitochondria, Golgi Apparatus, Endoplasmic Reticulum)
- Prokaryotes do not have compartmentalization

What is compartmentalization?

the formation of separate membrane-bound areas in a cell

What is the role of compartmentalization in cells

Compartmentalization allows cells to maintain ideal conditions for enzyme activity. So, it makes the cell more efficient in metabolism.

What is the role of the nucleus in a cell?

The nucleus contains the cell's DNA and contains coded instructions for making proteins and other important molecules.

What is the mitochondria and its role?

A double-layered membrane organelle which uses glucose to produce ATP.

What is the golgi apparatus?

Complex of folded membranes that process, package, and deliver proteins and lipids from the ER

What are centrosomes?

an organelle near the nucleus of a cell that contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division.

What is the role of smooth Endoplasmic Reticulum (SER)

Fatty acid and steroid synthesis; detoxifies toxic substances

What is the function of rough endoplasmic reticulum (RER)

An endomembrane system covered with ribosomes where many proteins for transport are assembled and stored.

What are vesicles?

membranous sacs that are used to transport materials in the cell

Structure of a nucleus (5 parts)

1. Nuclear envelope: double membrane surrounding nucleus, outer membrane continuous with the (R)ER of the cell.

2. Nuclear pores: allow the passage of larger molecules, such as mRNA, out of the nucleus.

3. Nucleoplasm: granular, jelly-like material making up the bulk of the nucleus.

4. Chromosomes: protein-bound, linear DNA.

5. Nucleolus: small spherical region in nucleoplasm. Manufactures ribosomal RNA and assembles ribosomes.

What is a polar molecule?

a molecule in which the charges are unevenly distributed

What is a phospholipid?

A special kind of lipid with a water-loving phosphate group based head and 2 water-fearing fatty acid tails

What is a triglyceride?

a lipid made of one glycerol and three fatty acids

What is a glycosidic bond? Draw structure

when two monosaccharide rings are bonded using a C-O-C bond

What is a protein? Draw structure

chain of amino acids

What is a peptide bond? Draw structure

bond between amino acids

types of proteins in cell membrane

enzymes, receptor proteins, hormones, transport channels

function of integral proteins

transport proteins, enzymes, or receptors

Function of peripheral proteins

provide points of attachment for cytoskeleton, acts as hormone

Function of glycoproteins (integral protein)

cell-cell recognition

3 functions of globular proteins and structural note (integral protein)

regulation of pH, regulation of metabolism, body defense. Contains oligosaccharide chain

function of cholesterol in cell membrane

cell membrane integrity - keeps it solid.

What is uniport?

one molecule in one direction

What is symport?

two molecules move in the same direction

What is antiport?

two molecules move in opposite directions

Is the pancreas endocrine or exocrine?

both. It is heterocrine.

What types of cells do the pancreas have?

alpha cells and beta cells

What are the alpha and beta cells called?

Islets of langerhans

What hormone do the beta cells release?

Insulin

What hormone do the alpha cells release?

Glucagon

What is the polysaccharide of glucose?

glycogen

What is the standard level of glucose in blood

80-120 milligrams per deciliter

What is the process for how blood sugar levels are maintained

Chemoreceptors on the cell membranes recognize high levels of sugar. Insulin is then released because of these chemoreceptor signals. Insulin signals cells to absorb the glucose and use it as energy and to take the excess sugar and store it as glycogen in the liver. This brings the concentration of sugar back to 80-120 mg/dl.

What is a high level of blood sugar called?

Hyperglycemia

What is a low level of blood sugar called?

Hypoglycemia

How does glucagon work?

Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream.

Which three organs are involved in water balance?

Hypothalamus, Pituitary and Kidney.

Relation of hypothalamus, pituitary gland and kidneys in water balance

Osmoreceptors in hypothalamus detect water concentration. If water is too much (hypotonic to the cells), it stimulates the pituitary gland to release less ADH (anti-diuretic hormone) and lets water be released into the urine. It works opposite way if there is less water (hypertonic to the cells), more ADH is released.)

What are the 7 conditions of filtered blood from the kidneys?

1. Proteins are same in quantity (not filtered)
2. Less urea and toxins
3. Less oxygen (used in respiration)
4. More CO2 (biproduct of respiration)
5. Ideal quantity of salts and ions
6. Ideal quantity of water
7. Less glucose (used in respiration)

What are the conditions of urine?

Undesired waste is removed from the blood. Along with that, glucose is not at all present (if there is glucose then that means excess glucose is being excreted, signaling diabetes)

Photosynthesis reaction

6CO2 + 6H2O ------> C6H12O6 + 6O2

Light dependent reaction

Breakdown of water

Light independent reaction

Organisation of glucose from CO2

Factors affecting photosynthesis

Light (green is worst, red and blue are best), chlorophyll, concentration of CO2, temperature

What are electron carriers and examples with their electronic reactions?

NAD+ and FAD are electron carriers which carry electrons in the form of energy. They get reduced to NADH + FADH2

NAD+ + 2h+ +2e- ----> NADH + H+
FAD + 2h+ +2e- ----> FADH2

Glycolysis

Glucose is phosphorylated by 2ATP (which turns to 2ADP)

Phosphorylation is endothermic, and thus the energy absorbed is released when it is broken into 2x triple carbon with phosphorous on the end. It is then phosphorylated more, to add phosphorous on the other end.

Then, the intermediate formed reduces NAD+ to NADH + H+ and the phosphorous leaves the intermediate to join the ATPs again. Thus, the 2ADPs will turn into 2ATPs for each intermediate. It will happen twice since there are two intermediates.