Cell biology worksheet with answers

How do enzymes speed up chemical reactions?

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

Who proposed the double-helix model of DNA in 1953?

1. AHershey and Chase
2. BWatson and Crick
3. CMeselson and Stahl
4. DMendel and Darwin

Which molecule brings amino acids to the ribosome during translation?

1. ADNA polymerase
2. BTransfer RNA (tRNA)
3. CRibosomal RNA (rRNA)
4. DMessenger RNA (mRNA)

How do steroid hormones such as cortisol mainly act on their target cells?

1. AThey bind a membrane receptor and open ion channels, changing the cell's membrane potential
2. BThey activate adenylyl cyclase from outside the cell
3. CThey cross the membrane and bind intracellular receptors that change gene transcription
4. DThey are taken up by phagocytosis and digested

A point mutation changes a codon for an amino acid into a stop codon. What type of mutation is this?

1. ANonsense mutation
2. BMissense mutation
3. CSilent mutation
4. DFrameshift mutation

Glycolysis takes place in the:

1. AMitochondrial matrix
2. BInner mitochondrial membrane
3. CNucleus
4. DCytoplasm

In damaged tissue, cells swell, their membranes burst and the area becomes inflamed. Which type of cell death is this?

1. AMitosis
2. BApoptosis
3. CNecrosis
4. DSenescence

Avery, MacLeod and McCarty treated the transforming extract with different enzymes. Which result showed that DNA was the transforming principle?

1. ANone of the enzymes had any effect
2. BOnly DNase destroyed the transforming activity
3. COnly protease destroyed the transforming activity
4. DOnly RNase destroyed the transforming activity