Topic 1: Cell Biology Flashcards
Eukaryotic cells
Complex cell - all animal and plant cells
Prokaryotic cells
Small and simple cell - bacterial cells
Prokaryote
A single-prokaryotic celled organism
Mitochondria
Organelle which is the site of aerobic respiration in a cell
Ribosomes
Organelle where protein synthesis occurs
Structures of a bacterial cell (6)
1) Cell wall
2) Cell membrane
3) Cytoplasm
4) Single, free-floating circular strand of DNA
5) 1 or 2 small rings of DNA (plasmids)
6) Ribosomes
Centimetres, millimetres, micrometres, nanometres to metres
1) 1 cm –> 110^-2
2) 1 mm –> 110^-3
3) 1 um –> 110^-6
4) 1 nm –> 110^-9
Differentiation
The process by which a cell changes to become specialised for its job by developing different subcellular structures and becoming a different type of cell
Mitosis (6)
1) Interphase - DNA uncoiled, floats in nucleus
2) Prophase - DNA replicates and condenses forming X-chromosomes
3) Metaphase - X-chromosomes line up at equator
4) Anaphase - X-chromosomes split by cell fibres, two arms go to opposite ends of cell
5) Telophase - new nucleus forms around the two sets of chromosomes and cell membrane divides
6) Interphase II - DNA uncoils, two new cells made
Medical use of adult stem cells
Bone marrow stem cells can replace faulty blood cells
Medical use of embryonic stem cells
1) Can replace faulty cells like insulin-producing cells for diabetics
2) Can replace nerve cells for those paralysed
Arguments against stem cell research (3)
1) Stem cells = potential human life
2) Science should concentrate on developing other sources of stem cells
3) Banned in some countries
Arguments for stem cell research (3)
1) Helps many people
2) Suffering of patients > the rights of the embryo
3) Embryos used are from fertility clinics and unwanted
Diffusion
The net movement of particles from an area of high concentration to an area of lower concentration
Factors for the rate of diffusion (3)
1) Temperature
2) Concentration gradient
3) Surface area (for membranes)
Osmosis
The net movement of water molecules, across a partially permeable membrane, from an area of high water concentration to an area of lower water concentration
Active transport
The movement of particles, across a membrane, from an area of lower concentration to an area of higher concentration requiring energy
Examples of active transport (2)
1) Root hair cells in plants absorbing minerals from the soil
2) Bloodstream absorbing nutrients from the gut
Adaptations of exchange surfaces (3)
1) Thin membranes to reduce the distance to diffuse
2) Large surface area so lots of substances can diffuse
3) Connected by lots of blood vessels to diffuse quickly
Alveoli adaptations (4)
1) Thin walls
2) Enormous surface area
3) Good blood supply for quick absorption
4) Moist lining for dissolving gases
Villi (in the small intestine) adaptations (3)
1) Single layer of surface cells
2) Enormous surface area
3) Very good blood supply for quick absorption
Gills’ adaptations (4)
1) Tin surface layer
2) Gill filaments with lamellae increase surface area
3) Lots of blood capillaries
4) Large concentration gradient between water and blood
MICROSCOPY PRACTICAL
-
OSMOSIS PRACTICAL
-
