Applied healthcare sciences
*Add previous notes from tablet*
The cell cycle
The changes a cell goes through from its formation to its reproduction
Majority of organs and tissues in the body undergo growth, replacement and repair
Cells undergo duplication and separation of their DNA (Mitosis)
Cell division – regulated by internal and external factors, determining when the cells divide
and stop dividing
New cells will develop and mature to a functional status
Most cells are life-limited
Cell division is essential for:
- Body growth
- Tissue repair
- Reproduction
cell division processes
Mitosis
- In most body cells
- Replication of DNA, structured into chromosomes
- Two sets of 23 chromosomes in matched pairs (46 total)
- 22 general chromosomes (or autosomes)
- One pair of sex chromosomes: X and Y
Meiosis
- Reproductive cell division
- Two sets of chromosomes are separated, each germ cell has ONE set
- DNA from the pairs is shuffled by crossing over
- DNA from one part of the pair will shuffle with the DNA from the other one
- Each chromosome pair will come from each parent
- DNA of the resulting germ cells is different from the parents
- Ova and Sperm will come together during fertilisation to form a single cell (zygote)
- Zygote divides to form an embryo, then a foetus, then a child
, Cellular processes
Glycolysis – a breakdown of glucose to form smaller molecules
ATP – currency of energy within a cell
Glucose is normally broken down to form CO2 and ATP
Anaerobic Metabolism – takes place in the absence of oxygen and produces energy
Happens to enable the transfer of energy (fight or flight)
Aerobic metabolism – normal cellular state
38 ATP produced through the reaction of glucose and oxygen
Movement of substances
Passive membrane transport
- Diffusion of molecules down their concentration gradient (from high to low)
Diffusion
- Simple – facilitated – osmosis
- Movement of molecules from high to low concentration
- In gases, liquids and solutions
- Process is sped up when
Temp is raised
Concentration of the diffusing substance is increased
Smaller molecules will diffuse more rapidly
Osmosis
- Diffusion of water down its concentration gradient.
- Happens due to other molecules present being too large to pass through the
membrane pores
- A force where this occurs is the osmotic pressure
- Occurs until equilibrium is reached
Solutions on each side have the same volume, not the same concentration
(isotonic)
Isotonic solutions – equilibrium
Hypotonic solution – plasma becomes more diluted than the intracellular fluid within RBC.
- Water moves down concentration gradient across membrane into RBC & cells swell
Hypertonic solution – plasma becomes more concentrated than the IC fluid within the RBC
- Water will passively move, and cells shrink
*Add previous notes from tablet*
The cell cycle
The changes a cell goes through from its formation to its reproduction
Majority of organs and tissues in the body undergo growth, replacement and repair
Cells undergo duplication and separation of their DNA (Mitosis)
Cell division – regulated by internal and external factors, determining when the cells divide
and stop dividing
New cells will develop and mature to a functional status
Most cells are life-limited
Cell division is essential for:
- Body growth
- Tissue repair
- Reproduction
cell division processes
Mitosis
- In most body cells
- Replication of DNA, structured into chromosomes
- Two sets of 23 chromosomes in matched pairs (46 total)
- 22 general chromosomes (or autosomes)
- One pair of sex chromosomes: X and Y
Meiosis
- Reproductive cell division
- Two sets of chromosomes are separated, each germ cell has ONE set
- DNA from the pairs is shuffled by crossing over
- DNA from one part of the pair will shuffle with the DNA from the other one
- Each chromosome pair will come from each parent
- DNA of the resulting germ cells is different from the parents
- Ova and Sperm will come together during fertilisation to form a single cell (zygote)
- Zygote divides to form an embryo, then a foetus, then a child
, Cellular processes
Glycolysis – a breakdown of glucose to form smaller molecules
ATP – currency of energy within a cell
Glucose is normally broken down to form CO2 and ATP
Anaerobic Metabolism – takes place in the absence of oxygen and produces energy
Happens to enable the transfer of energy (fight or flight)
Aerobic metabolism – normal cellular state
38 ATP produced through the reaction of glucose and oxygen
Movement of substances
Passive membrane transport
- Diffusion of molecules down their concentration gradient (from high to low)
Diffusion
- Simple – facilitated – osmosis
- Movement of molecules from high to low concentration
- In gases, liquids and solutions
- Process is sped up when
Temp is raised
Concentration of the diffusing substance is increased
Smaller molecules will diffuse more rapidly
Osmosis
- Diffusion of water down its concentration gradient.
- Happens due to other molecules present being too large to pass through the
membrane pores
- A force where this occurs is the osmotic pressure
- Occurs until equilibrium is reached
Solutions on each side have the same volume, not the same concentration
(isotonic)
Isotonic solutions – equilibrium
Hypotonic solution – plasma becomes more diluted than the intracellular fluid within RBC.
- Water moves down concentration gradient across membrane into RBC & cells swell
Hypertonic solution – plasma becomes more concentrated than the IC fluid within the RBC
- Water will passively move, and cells shrink
