AS BIOLOGY OCR Depth Paper Predictions?

Ergh do you guys think it's gonna be a hard exam tomorrow?!?¿

Do we need to know any of the inorganic ions like the cations and anions for this exam tomorrow

Do we need to know any of the inorganic ions like the cations and anions for this exam tomorrow

I'm not quite sure however if we do......

Cations - Positive Charge

1. Calcium (Ca2+) - Increases bone, teeth, and cartilage rigidity, Involved in nerve impulse transmission , Acts as a cofactor for many enzymes (i.e. lipase ATPase and cholinesterase), Stimulates muscle contraction and regulates cell membrane permeability.

2. Sodium (Na+) - Regulates fluid balance (i.e osmotic pressure, water levels and maintenance), generates nerve impulses and muscle contraction, helps to maintain turgidity in plant vacuole.

3. Potassium (K+) - Again important for nerve transmission and muscle contraction, activates enzymes needed for photosynthesis, involved in synthesis and breakdown of glycogen and protein, maintains fluid levels in the body ect.

4. Hydrogen (H+) - Involved in the transport of oxygen and carbon dioxide (Bohr effect), Involved in photosynthesis and respiration, regulation of blood pH and affects the pH of substances (more H+ = more acidic)

5. Ammonium (NH4+) - Component of nucleic acids, Absorbed from the soil by plants then can make amino acids ect, Maintains pH in human body, involved in the nitrogen cycle.

Anions - Negative Charge

1. Nitrate (NO3-) - Pretty much same for Ammonium, Component of nucleic acids, amino acids, proteins, and chlorophyll, Used to make hormones made of proteins which contain nitrogen (i.e. insulin - regulates blood glucose levels), Component of the nitrogen cycle.

2. Hydrogencarbonate (HCO3-) - Acts as a buffer, helps to maintain blood pH, Involved in the transport of carbon dioxide into and out of the blood.

3. Chloride (Cl-) - Cofactor for amylase, involved in the chloride shift which helps to maintain blood pH during gas exchange, involved in some nerve impulses, used to produce hydrochloric acid in the stomach, Regulates affinity of haemoglobin to oxygen through allosteric effects, helps in the production of urine in the kidney and maintaining water balance.

4. Phosphate (PO4^3-) - Increases bone, teeth and cartilage rigidity (bonds with calcium to produce calcium phosphate which strengthens bones), Involved in photosynthesis and respiration reactions, helps roots grow in plants, Component of ATP, phospholipids, nucleic acids and several other enzymes.

5. Hydroxide (OH-) - Affects the pH of substances and regulates blood pH (the more OH- ions a solution has the more alkali it is).

Thanks that's so helpful. My teacher didn't go through this very well.

Can someone explain the test for proteins pleazd

I'm not quite sure however if we do......

Cations - Positive Charge

1. Calcium (Ca2+) - Increases bone, teeth, and cartilage rigidity, Involved in nerve impulse transmission , Acts as a cofactor for many enzymes (i.e. lipase ATPase and cholinesterase), Stimulates muscle contraction and regulates cell membrane permeability.

2. Sodium (Na+) - Regulates fluid balance (i.e osmotic pressure, water levels and maintenance), generates nerve impulses and muscle contraction, helps to maintain turgidity in plant vacuole.

3. Potassium (K+) - Again important for nerve transmission and muscle contraction, activates enzymes needed for photosynthesis, involved in synthesis and breakdown of glycogen and protein, maintains fluid levels in the body ect.

4. Hydrogen (H+) - Involved in the transport of oxygen and carbon dioxide (Bohr effect), Involved in photosynthesis and respiration, regulation of blood pH and affects the pH of substances (more H+ = more acidic)

5. Ammonium (NH4+) - Component of nucleic acids, Absorbed from the soil by plants then can make amino acids ect, Maintains pH in human body, involved in the nitrogen cycle.

Anions - Negative Charge

1. Nitrate (NO3-) - Pretty much same for Ammonium, Component of nucleic acids, amino acids, proteins, and chlorophyll, Used to make hormones made of proteins which contain nitrogen (i.e. insulin - regulates blood glucose levels), Component of the nitrogen cycle.

2. Hydrogencarbonate (HCO3-) - Acts as a buffer, helps to maintain blood pH, Involved in the transport of carbon dioxide into and out of the blood.

3. Chloride (Cl-) - Cofactor for amylase, involved in the chloride shift which helps to maintain blood pH during gas exchange, involved in some nerve impulses, used to produce hydrochloric acid in the stomach, Regulates affinity of haemoglobin to oxygen through allosteric effects, helps in the production of urine in the kidney and maintaining water balance.

4. Phosphate (PO4^3-) - Increases bone, teeth and cartilage rigidity (bonds with calcium to produce calcium phosphate which strengthens bones), Involved in photosynthesis and respiration reactions, helps roots grow in plants, Component of ATP, phospholipids, nucleic acids and several other enzymes.

5. Hydroxide (OH-) - Affects the pH of substances and regulates blood pH (the more OH- ions a solution has the more alkali it is).

Cell division, Enzymes, Evolution, Protein Synthesis, Biological tests, Biological molecules

Use biuret solution (copper sulfate and sodium hydroxide)
Colour change from blue -> purple if proteins are present

Is this the test were you need to make it alkaline first or was that another :3

Is this the test were you need to make it alkaline first or was that another :3

Anyone able to summarise gas exchange in fish, please?

In fish their is a counter-current system so blood and water flow in an opposite direction over the gill plates. Water with a high oxygen concentration always flows next to blood with a low oxygen concentration-this maintains a steep concentration gradient.

The floor of the buccal cavity lowers, which increases volume and decreases the pressure inside the buccal cavity. This sucks water inside and the mouth closes and the buccal cavity floor is raised. The volume decreases and the pressure increases which forces the water out of the gill filaments. The gills are protected by the operculum.