Detective Biology Quiz | Biology

Quiz Answer Key and Fun Facts

1. Unlike some other biological molecules, you are soluble. More specifically, you are water soluble, meaning that you can interact with water molecules via hydrophilic groups at your surface. Which other term is used to describe molecules which interact with hydrophobic solvents?

Answer: Lipid soluble

Lipid solubility (or lipophilicity) is an umbrella term for substances which dissolve not only in lipid solvents, but in other non-polar solvents such as hexane.
Hydrophilic substances dissolve as they become surrounded by water molecules (which are polar) and are said to be solvated (or hydrated).

2. Your structure is carefully controlled by the chemical character of the units of which you are composed. Which weak and transient, yet widespread chemical interactions, also known as London dispersion forces, are involved in keeping many biological structures together?

Answer: Van der Waals forces

Despite being very weak and transient, van der Waals forces have an additive effect, and so the more of these interactions which occur between two molecules, the higher the substance's melting/boiling point.
These interactions arise due to the attraction between two temporarily induced dipoles.

3. You are not only found in animals, but in plants, fungi and prokaryotes (e.g. bacteria). One example of the type of molecule you are, called RuBisCO, is found in plants and is one of the most abundant molecules in the planet. Which process, associated with photosynthesis, is this molecule involved with?

Answer: The Calvin cycle

The Calvin cycle (named for Melvin Calvin, one of its discoverers) is part of a series of reactions which make up the "dark reactions" in photosynthesis. This cycle (which occurs in the stroma of a chloroplast) fixes carbon dioxide, eventually synthesising carbohydrates.

The energy which drives the dark reactions is provided by the electron transfer chain in the light-dependent reactions of photosynthesis.

4. You may also be involved with other important processes, such as the conversion of glucose into pyruvate - glycolysis. Where, specifically, does glycolysis occur in the human body?

Answer: In the cell cytoplasm

Glycolysis is a key reaction in respiration, and therefore takes place not only in humans, but in all other animals and plants. The pyruvate produced by glycolysis is then converted into acetyl coenzyme A, before entering the Krebs cycle (or citric acid cycle, as it is also known).
Glycolysis is also present when our bodies carry out anaerobic respiration, but its products do not enter the Krebs cycle and so do not yield anywhere near the amount of ATP (energy) as aerobic respiration.

5. As well as in photosynthesis and glycolysis, you may be found in the nucleus of a cell, where DNA replication and mRNA synthesis occur. What is the fate of mRNA after it is synthesised?

Answer: It attaches to ribosomes in the cytoplasm

mRNA is synthesised in the nucleus, but is small enough to leave via the nuclear pores. In the cytoplasm, it attaches to a ribosome, where protein synthesis takes place. tRNAs (small, folded strands of RNA) carry specific amino acids to the mRNA and the amino acids are joined by the ribosome.

6. Although you are commonly found in humans, bacteria are needed to perform some functions which you cannot carry out. True or false - the human body is made up of almost as many bacterial cells as our own cells.

Answer: False

Bacterial cells in our body actually outnumber our own eukaryotic cells by 10 to 1. In the human intestine alone, there are believed to be over 500 strains of bacteria at any one time. The vast majority of these bacteria either do us no harm, or are actually beneficial to our health.
Mitochondria, which are essential to the process of respiration (and therefore life) are believed to be ancient prokaryotes, which were engulfed by larger cells, with both entities benefiting from the union.

7. You are not only useful for processes in the human body, but you are now used in many industrial processes, and even in laundry detergents. For these uses, specific types of organisms are of interest. What general name is given to organisms which live in very cold or very hot conditions?

Answer: Extremophiles

Extremophiles are often found on the sea floor, by hydrothermal vents. An example of an organism found in this environment is the tube worm. Vestimentiferens (a type of tube worm) can be several foot long and derive nutrients from sulphides from the vents. Their odd appearance gave them their name, which literally means "worms in dinner jackets".

8. There have been many man-made products which carry out the same functions which you are capable of performing, but none have even come close to doing it with the same efficiency. However, a huge step was taken in 2010 when it was claimed that the first synthetic life-form had been created in a U.S laboratory. What quirky name was given to this organism?

Answer: Synthia

Predictably, this project attracted much debate, with the familiar cries of scientists "playing God". However, although Craig Venter created this life-form which almost certainly would have never existed otherwise, his creation fell somewhat short of the miracle which occurs when an organism is conceived naturally, or even when a single cell divides.

Instead of constructing a genome nucleotide by nucleotide (which is what happens in nature), Venter purchased segments of DNA, which were then stitched together to create his synthetic genome.

9. Unfortunately, many examples of the type of molecule which you are are rather unimaginatively named. Which molecule is a protein which is involved with proteolysis, and is similarly unimaginatively named for its widespread presence in the cell?

Answer: Ubiquitin

As well as synthesising proteins, a cell must degrade proteins which have become denatured or damaged. Ubiquitin attaches to damaged proteins, marking them for destruction. A ubiquitinated protein is then destroyed via proteolysis, carried out by a proteosome in the cytoplasm.

10. Having gathered together the clues provided in the previous 9 questions, can you identify the type of biological molecule you are?

Answer: Enzyme

Clue 2 tells us that you are made up of many units, which determine your structure. This allows you to deduce that you are a macromolecule. Clue 1 (that you are soluble) removes the possibility that you are a structural molecule.

Clues 3, 4 and 5 give clues about the roles you perform in living organisms. Those who are familiar with RuBisCO may have been given a big hint here. Note that the ribosomes mentioned in question 5 also have catalytic ability, but this is due to RNA rather than proteins.

Clue 6 tells us that there are different "versions" of this molecule in eukaryotes and prokaryotes. Clue 7 tells us that these molecules have different optimal temperatures, and clue 8 alludes to the incredible efficiency with which these molecules carry out their jobs.

Finally, clue 9 talks about some of the rather unimaginative names given to these molecules. These include reverse transcriptases, flippases and unfoldases.

Source: Author doublemm

This quiz was reviewed by FunTrivia editor gtho4 before going online.
Any errors found in FunTrivia content are routinely corrected through our feedback system.

Detective Biology Trivia Quiz

You are a biological molecule, but you're not sure which one. Questions 1 to 9 in this quiz will provide clues about your true identity, as well as testing your knowledge of general biology, before Q.10 gives you the opportunity to identify yourself.

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