Lab Exam 1 Flashcards
Procedure and what Benedicts Assay Tested
- The presence of a reducing sugar by searching for carbonyl group in the chain form of a sugar
- Not found in ring form as carbonyl group is lost due to bonds
- Copper bydroxide was mixed in an alkaline pH and heated for 3 mins and tested for solubility; cloudy illustrates it was insoluble and therefore shows a reducing sugar as Copper hydroxide reduced is cuprous oxide which is insoluble in water
Samples tested in Carbohydrate Experiment
- Glucose(reducing monosaccharide)
- Fructose(Reducing Monosaccharide)
- Galactose(Reducing Monosaccharide)
- Lactose(reducing disaccharide)
- Maltose(Reducing Disaccharide)
- Sucrose(Non reducing disaccharide)
- Starch(non-reducing disaccharide)
Water
Procedure and what Barfords Assay Tested For:
- The presence of a monosaccharide
Copper hydroxide was mixed in an acidic pH where only monosaccharide reducing sugars can work; a positive reaction of slightly turbid or color change indicates a monosaccharide
Procedure and what Iodine Assay Tested for:
- The presence of Starch
2 drops of Iodine was mixed with samples an interactions of the covalently linked coiled glucose units was watched; if interacts with coils it forms a blue black complex and if not remains yellowy
Relationship between reducing sugars and type of sugar
All monosaccharides are reducing sugars, but not all disaccharides are reducing sugars
Substances and Procedure in Biuret Assay
- Egg Albumin
- Gelatin
- Sucrose
- Water
15 drop of biuret regent(copper sulfate in alkaline solution mixed in each solution with the goal of denaturing tertiary and secondary protein structure to highlight primary structure which exposes peptide bonds by causing the reagent to change to a violet color
Substances in Lipid Tests
- Vegetable oil(lipid,
- Olive oil(lipid)
- Gelatin
- Sucrose
Water
Procedure and What Miscibility Assay tested for:
- 3mL of mixture was mixed with 3mL of water and vigorously mixed
Looking for the hydrophobic/hydrophilic nature of substances: if substances did not mix, indicating they are hydrophobic and therefore a lipid
Procedure and what Sudan Black Tested For
- 3mL of mixture and water were vigorously mixed
- 4 drops of Sudan black were added; as it is a hydrophobic it gets homogenously mixed with other hydrophobic substances; if the substance on top is stained black then it is hydrophobic
Summary of Cellular Respiration Equation
Glucose + 6O2 -> 6 Co2 + 6H2O + energy(heat and 36-38 ATP)
Procedure of Cellular Respiration Prac
- Prepared respirometers by adding an absorbent cotton ball at the bottom before adding 20 drops of 1m KOH
- A non absorbent cotton ball was added on top before the subjects were placed inside
- Cork was applied with inserted pipets before being placed in water baths
- Oxygen consumption was measured by water movement in respirometer away
Purpose of KOH in CR
- Potassium hydroxide will react with Co2 to produce solid potassium carbonate which will remove all co2 produced during cellular respiration in order to accurately show how much O2 is being consumed
- As any gaseous volume change in respirometer is now due to O2
Results of Cellular Respiration Prac
- Germinating peas had the highest rate of oxygen consumption compared to crickets but crickets had high metabolic rate as they produced more O2 relative to their weight
- Oxygen consumption in living things should show a linear positive trend
Photosynthesis Equation
6CO2 + 12 H2O + light energy-> 2 C3H6O3 + 6O2 + 6H2O
Purpose of Photosynthesis Lab
- To examine the effect of light intensity(number of photons per time) on the rate of photosynthesis
- To separate pigments of chloroplast extract from spinach leaves by paper chromatography
- To then construct an absorption spectrum of chlorophyll solution using a spectrophotometer