- Prokaryotes have no membrane bound organelles? T/F
- All cells possess a cell wall? T/F
- The mitochondria once existed on its own? T/F
- Prokaryotes has 80s ribosomes? T/F
- Ribosomes possess a single membrane? T/F
- The cytosol is the liquid part of the cell? T/F
- In differential centrifugation the nucleus is precipitated first? T/F
- Eukaryotes possess a nucleus? T/F
- Membrane bound ribosomes and free ribosomes synthesis protein that have the same purpose? T/F
- The nucleolus is a dense region found in the nucleus? T/F
Over the past five weeks three topics have been covered in the lectures: The Cell, Carbohydrates and Amino acids. After each topic was taught we were given a quiz. At first I didn’t really like the idea of a quiz every week but now I can appreciate its usefulness since it ensures that I am constantly studying. Which means when final exams come around I will already have the basic ideas of each topic down.
Also the fact that none of the slides used in the lectures were going to be posted on myelearning really worried me since the internet is not readily available to me. Thus making the videos on YouTube more difficult to access so you could have imagine my reaction to creating a blog. However things are okay.
This lab involved two major parts: (1)Standardization and (2)the Estimation of Ascorbic Acid in canned juice.
In part one the ascorbic acid was placed in a burette and 20 ml of dichlorphenol-indophenol (DCPIP) solution was pipetted into an Erlenmeyer flask. Then the DCPIP was titrated with the ascorbic acid until a colour change of pink to colourless was observed. This took approximately 30 – 120 seconds to occur so great attention was needed to avoid overshooting during the this titration.
For part two there was two kind of juice to be titrated; orange and apple. In each bench the students were divided into groups, before the lab. Each group did part one and used only one of the juice for part two. Then the demonstrator made apple and orange stock: He/she poured 2ml of the canned juice (orange/apple) into 500ml beaker and acidified it with 0.2ml of glacial acetic acid. The volume was made up to 50ml with distilled water and mixed thoroughly. The rest was done by the students.
25ml of the stock made was transferred to a 50ml conical flask, using a measuring cylinder. 2oml of 5% metaphosphoric acid was added and the volume made up to 50ml by adding 5ml of distilled water. This solution was then transferred to a burette and approximately three 5ml volumes of DCPIP was titrated until a colour change of pink to colourless was observed. This titration took a longer time and as such large quantities of the juice preparation was used for each titration.
This gives the functions of some structures of the cell along with a picture of the structure. I hope it helps someone.
My first biochem lab of the semester was quite interesting and made up of several tests for carbohydrates and lipids as well as for proteins and amino acids. The tests for carbohydrates and lipids included the Molisch test, Benedict’s test, Seliwanoff’s test, Modified Barfoed’s test, Bial’s test, Iodine test, Acid Hydrolysis of Sucrose, Sudan III test and an Emulsion test.The following are tesst for protein and amino acids: the Biuret reaction, protein precipitation and the Ninhydrin reaction. can you guess what each are for?
My name is Adanna Phillip. I am a first year student at UWI pursuing a Bsc General in Biology and Chemistry. For most of my life my vision was to become a Medical Doctor but like life plans and minds change. thus I am officially unsure of my career choice.