answers 2025\2026 A+ Grade
Definition of biochemistry
- correct answer chemistry of life; how properties of organisms relate to their molecules
What are the 3 things biochemists study?
- correct answer 1. The relationship between structure and function of biomolecules
2. Chemical reactions of organisms (metabolism)
3. Communication within and among organisms
What are bulk elements?
- correct answer Elements that are abundant in living organisms
What are trace elements?
- correct answer Elements that are less abundant in organisms but still crucial for life
Name the bulk elements (10)
- correct answer H, Na, K, Ca, C, N, O, P, S, Cl
Name the trace elements (13)
- correct answer Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W, Se, I
What's another word for a firefly?
- correct answer Lightning bug
Explain the chemical reaction of lightning bugs
- correct answer The chemical reaction is called bioluminescence. Proteins regulate, produce, and
degrade the light-emitting compound called luciferin. Luciferin, when acted upon by a protein, glows as
bugs move. This chemical reaction is regulated by the protein (enzyme) called luciferase.
, How many naturally occurring elements exist? How many are found in living organisms and what kind of
elements?
- correct answer 90 naturally occurring elements, less than 30 elements are found in living organisms.
Most of these 30 elements are smaller non-metals.
Why are smaller elements favored for living organisms?
- correct answer They can form stable, covalent bonds
How are strong bonds formed?
- correct answer Strong bonds form by significant overlap of atoms, such as carbon and hydrogen,
permitting them to share electrons
Why is the strong bond good for living organisms?
- correct answer The bond that forms requires significant energy to break it. This means the bonds can
withstand mechanical and thermal pressures through the growth of hair/skin for protection.
Do larger elements form stable covalent bonds?
- correct answer No
Describe the role of Iron as a larger element
- correct answer Iron has a critical role in hemoglobin for oxygen transport in vertebrates.
Forms an ion capable of binding to oxygen.
Describe H and O in H2O
- correct answer Both H and O are found in large amounts. They are small atoms that form strong bonds.
When bonded as H2O, they form a small, polar molecule that solvates and dissolves many compounds.
H2O makes up ___% or more of living things
- correct answer 70%
Some plant species are ___% water by mass
- correct answer 90%