Biomolecules & Energy
What are the four main types of biomolecules?
Carbohydrates, lipids, proteins, and nucleic acids.
What is the function of DNA in cells?
It stores genetic information that directs protein synthesis.
What is homeostasis?
The process of maintaining a stable internal environment.
What is the main source of energy for life on Earth?
The Sun.
What is an example of a biotic factor in an ecosystem?
Plants, animals, bacteria, fungi (any living organism).
How do enzymes speed up chemical reactions in the body?
They lower the activation energy needed for reactions to occur.
How does RNA differ from DNA?
RNA is single-stranded, has ribose sugar, and uses uracil instead of thymine.
How does the cell membrane help maintain homeostasis?
It controls what enters and exits the cell.
Describe the difference between a food chain and a food web.
A food chain is a linear energy flow; a food web is interconnected food chains.
What is an abiotic factor? Provide an example.
A non-living environmental factor, such as sunlight, water, temperature, or soil.
Compare the functions of carbohydrates and lipids in energy storage.
Carbohydrates provide quick energy, while lipids store long-term energy.
What is the role of mRNA in protein synthesis?
It carries the genetic code from DNA to ribosomes for translation.
What is the difference between passive and active transport?
Passive transport does not require energy, while active transport does.
What role do decomposers play in an ecosystem?
They break down dead organisms and recycle nutrients into the environment.
How do predators and prey interact in an ecosystem
Predators regulate prey populations, preventing overpopulation and maintaining balance.
What happens to an enzyme when it is exposed to extreme heat or pH levels?
Describe the process of transcription and translation
Transcription creates mRNA from DNA; translation uses mRNA to build proteins.
How do osmosis and diffusion help cells maintain balance?
They allow water and molecules to move across membranes to maintain equilibrium.
How do changes in biodiversity impact an ecosystem’s stability?
Higher biodiversity increases resilience; low biodiversity makes ecosystems more vulnerable to disturbances.
What happens when an invasive species is introduced into an ecosystem?
It disrupts food chains, outcompetes native species, and can cause population declines or extinctions.
Explain how ATP provides energy for cellular processes
ATP releases energy when a phosphate group is removed, forming ADP.
Explain how a mutation in DNA can affect an organism
It can change a protein’s structure and function, potentially causing diseases or traits.
Describe the sodium-potassium pump and its role in nerve cell function
It moves sodium out and potassium into the cell, helping maintain electrical charge for nerve impulses.
Explain how energy moves through an ecosystem using trophic levels.
Energy flows from producers to primary consumers to higher-level consumers, decreasing at each level.
Explain the role of keystone species in an ecosystem
Keystone species have a critical role in maintaining ecosystem balance; their removal can cause major disruptions.