Cell Types & Viruses
Which organelle in eukaryotic cells produces energy in the form of ATP?
Mitochondria
Which biomolecule forms long chains of glucose molecules for energy storage in plants?
Starch
Which gas is produced as a waste product of photosynthesis?
Oxygen (O₂)
What is the shape of DNA and who discovered it?
Double helix; Watson and Crick
During meiosis, what separates during anaphase I?
Homologous chromosomes
How does a prokaryotic cell differ from a eukaryotic cell in terms of DNA?
Prokaryotic DNA is circular and free-floating; eukaryotic DNA is linear and in a nucleus
What type of lipid forms a barrier around cells and is amphipathic?
Phospholipid
During photosynthesis, which molecule is reduced to form glucose?
Carbon dioxide (CO₂)
If a DNA strand has the sequence A-T-G-C, what is the complementary strand?
T-A-C-G
How does crossing over increase genetic diversity?
It shuffles alleles between homologous chromosomes
Why can viruses infect only specific types of cells?
Because they have specific receptor proteins that match host cell surfaces
Why are enzymes specific to only one type of reaction?
Because the shape of the active site matches only certain substrates
What is the main energy currency of the cell?
ATP
What is the main difference between mitosis and meiosis?
Mitosis produces 2 identical cells; meiosis produces 4 genetically unique cells
What is the role of tRNA in gene expression?
It brings amino acids to the ribosome during translation
Some viruses contain RNA instead of DNA. How does this affect replication?
RNA viruses must use reverse transcriptase (for retroviruses) or RNA-dependent RNA polymerase to replicate
What happens to reaction rates if an enzyme is saturated with substrate?
Rate levels off (maximum velocity, Vmax)
How are photosynthesis and cellular respiration related?
The products of one are the reactants of the other
Why are checkpoints important in the cell cycle?
They prevent damaged or incomplete DNA from being passed on
What determines which genes are expressed in a cell?
Which genes are turned on or off
Describe one way bacterial cells exchange genetic material besides binary fission.
Conjugation, transformation, or transduction
How can inhibitors affect enzyme activity differently (competitive vs. noncompetitive)?
Competitive inhibitors bind to active site; noncompetitive inhibitors bind elsewhere and change the enzyme’s shape
In which organelle does cellular respiration take place?
Mitochondria
How can mutations in DNA affect protein function?
They can change amino acid sequence, potentially altering protein shape and function
Explain how a mutation in a regulatory gene could affect cell differentiation.
It could turn genes on or off incorrectly, leading to abnormal cell development