Cell biology worksheet with answers

How do enzymes speed up chemical reactions?

1. AThey change the reaction's final equilibrium
2. BThey are used up in the reaction
3. CThey lower the activation energy
4. DThey raise the temperature of the cell

Proteins are polymers of which monomers?

1. AGlycerol molecules
2. BSimple sugars
3. CAmino acids
4. DNucleotides

Which organelle produces most of the cell's ATP?

1. AMitochondrion
2. BGolgi apparatus
3. CLysosome
4. DRibosome

Which molecules can cross a phospholipid bilayer most easily by simple diffusion?

1. AProteins such as albumin
2. BIons such as Na⁺ and K⁺
3. CLarge polar molecules such as glucose
4. DSmall non-polar molecules such as O₂ and CO₂

A codon consists of:

1. AThree amino acids
2. BThree nucleotides on mRNA that code for an amino acid or a stop signal
3. CA whole gene
4. DOne nucleotide

Cyclin-dependent kinases (CDKs) that drive the cell cycle become active when they bind to:

1. ARibosomes
2. BTubulins
3. CCyclins
4. DHistones

A mutant Ras protein cannot hydrolyse GTP. What is the effect on cell signalling?

1. ARas stays active and sends constant growth signals
2. BRas stays inactive and growth signals stop
3. CRas moves into the nucleus and blocks transcription
4. DRas is broken down faster

In the Hershey–Chase experiment, phages labelled with ³²P and ³⁵S infected bacteria. What was found inside the bacteria?

1. ANeither label, because phages stay outside
2. BEqual amounts of both labels
3. CMostly ³²P, showing DNA enters the cell
4. DMostly ³⁵S, showing protein enters the cell