B1&B2: Cells, Cell division and Stem cells Flashcards
Cell membrane
controls what enters and leaves the cell
Cytoplasm
site of chemical reactions
Nucleus
contains the genetic material (DNA)
Ribosome
site of protein synthesis
Mitochondria
site of respiration
Cellulose cell wall
strength and support to the plant. It is fully permeable.
Chloroplast
site of photosynthesis
Large permanent vacuole
contains cell sap
Diffusion
the movement of substances from an area of high concentration to an area of low concentration. E.g. oxygen molecules diffuse from the lungs into the blood stream
Osmosis
the movement of water molecules from an area of high concentration to an area of low concentration across a partially permeable membrane
Active transport
the movement of substances from an area of low concentration to an area of higher concentration. Against a concentration gradient, requires ATP energy and a carrier protein in the cell membrane.
E.g. glucose is sometimes actively transported from your small intestine into the bloodstream.
E.g. mineral ions in water are actively transported from the soil into the root hair cells.
Interphase
cell grows in size, DNA and organelles replicate.
Mitosis
replicated chromosomes line up along the centre of the cell and get pulled to opposite poles. Nucleus divides.
Cytokinesis
cell membrane and cytoplasm divide to form 2 new identical daughter cells
What is a stem cell?
An unspecialised cell, that can differentiate into many other cell types.
