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SingaporeBiology

Cell Biology

7 dot points across 7 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do cells detect signals from outside and convert them into an internal response?

Explain the principles of cell signalling, including the roles of receptors, signal transduction and second messengers
A focused answer to the H2 Biology Cell Biology outcome on cell signalling. The stages of signalling (reception, transduction, response), membrane and intracellular receptors, second messengers such as cyclic AMP, and how signalling cascades amplify a response.
8 min answer →

How does the ultrastructure of prokaryotic and eukaryotic cells relate to their functions, and how do we distinguish the two?

Describe the ultrastructure of prokaryotic and eukaryotic cells and relate the structure of organelles to their functions
A focused answer to the H2 Biology Cell Biology outcome on cell ultrastructure. The organelles of eukaryotic cells and how their structure fits their function, the simpler organisation of prokaryotes, and the key differences between the two cell types.
9 min answer →

How do the four levels of protein structure arise, and how does the resulting three-dimensional shape determine a protein's function?

Describe the four levels of protein structure and explain how structure determines function, including the effect of denaturation
A focused answer to the H2 Biology Cell Biology outcome on protein structure. The primary, secondary, tertiary and quaternary levels, the bonds that hold each level, how shape determines function, and what happens during denaturation.
9 min answer →

How is the cell cycle organised and controlled, and how does mitosis produce two genetically identical cells?

Describe the cell cycle and the stages of mitosis, and explain the significance of mitosis and the consequences of uncontrolled division
A focused answer to the H2 Biology Cell Biology outcome on the cell cycle and mitosis. Interphase and its sub-phases, the stages of mitosis, the role of checkpoints, the genetic significance of mitosis, and how loss of control leads to cancer.
9 min answer →

What is the molecular structure of the cell surface membrane, and how does the fluid mosaic model account for its properties?

Describe the fluid mosaic model of membrane structure and relate the roles of phospholipids, proteins, cholesterol and carbohydrates to membrane function
A focused answer to the H2 Biology Cell Biology outcome on membrane structure. The phospholipid bilayer, the proteins, cholesterol and carbohydrates embedded in it, and how the fluid mosaic model explains membrane fluidity, selective permeability and cell recognition.
8 min answer →

How do the structures of carbohydrates, lipids, proteins and nucleic acids determine their biological functions?

Describe the structure of carbohydrates, lipids, proteins and nucleic acids and relate structure to function
A focused answer to the H2 Biology Cell Biology outcome on biological molecules. The monomers and polymers of carbohydrates, lipids, proteins and nucleic acids, the condensation and hydrolysis reactions that join and split them, and how structure fits function.
9 min answer →

How do substances cross the cell surface membrane, and what distinguishes passive from active transport?

Explain the mechanisms of diffusion, facilitated diffusion, osmosis, active transport, endocytosis and exocytosis across membranes
A focused answer to the H2 Biology Cell Biology outcome on membrane transport. Simple and facilitated diffusion, osmosis and water potential, active transport with carrier proteins and ATP, and bulk transport by endocytosis and exocytosis.
9 min answer →