Chapter I and II Flashcards
unspecialised animal cells have
- cell membrane
- cytoplasm
- mitochondria
unspecialised plant cells
- a cellulose cell wall
- a permanent vacuole
- chloroplasts (green parts of the cell)
→ chlorophyll for photosynthesis
cells
- all living organisms are based on units known as cells
-most cells share basic features, but the size, shape & specialised features of the cells are tied to their function
organisation levels for nuclear organisms
- organ systems
- organ
- tissue
- cell
- organelles
- molecules
- atoms
organ systems
group of organs working together to perform body functions e.g. digestive system
organ
group of tissues working together to perform a specific function
tissue
group of cells working together (cell same structure)
cell
structural and functional unit of all living organisms
organelles
cell structure having a specific function within the cell
molecules
group of atoms bonded together
atoms
smallest component of an element
movement in and out of cells
- cell membrane shows selective permeability*
- whether a molecule can pass through the cell membrane depends on its SIZE and its ELECTRICAL NATURE
*the ability of a substance to allow gases or liquids to go through it
the phospholipid bilayer is
- highly permeable to small non polar (hydrophobic) molecules like O2, CO2, small lipids
- slightly permeable to small polar molecules like H20
-not permeable to large polar molecules like glucose and ions (charged atoms and molecules)
diffusion
– spontaneous random movements
– (kinetic energy)
– no energy needed
– particles move from a high concentrated region to a less concentrated region
osmosis
osmosis is the diffusion of solvent/water molecules across a partially permeable membrane from a lower to higher solute concentration (→up the solute gradient)
FFFFFfacilitated diffusion
→diffusion of a molecule through a specific transport protein
- channel protein
- carrier protein
active transport
transport of a molecule against the concentration gradient through specific proteins (carriers) requiring energy
macromolecules
a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.
macromolecules pass the membrane through endo- and exocytosis
→ mecanism of active transport which allows the enty or exit of big particles & macromolecules
phagocytosis
cell eating
pinocytosis
cell drinking
the endocrine system
series of organs called “glands” which secrete chemicals called hormones
glycaemia
concentration of glucose in the blood
→ normal values around 1g/L
is controlled by 2 antagonistic hormones (opposite reactions) both are secreted by the pancreas
insulin
lowers glycaemia
glucagon
raises glycaemia
cell membrane functions
- regulate the transport of materials that are entering or leaving cell
- communicate between cells
- separates the interior from the exterior
mitochondrion (mitochondria) structure
have double/ 2 membrane
- outer membrane is smooth
- the inner membrane huge surface area efficient for chemical reactions
aerobic respiration
mitochondrion (mitochondria) function
powerhouse of the cell
- most mitochondrial reactions involve the production of usable cellular energy called adenosine triphosphate atp
nucleus
- contains genetic information, the DNA
- it often appears in the form of chromosomes which vary in the number depending on the species
→they carry all infromation necessary for the cell to exist
chromatin is a mixture of DNA and proteins
chromosomes are only visible during cell division
homeostasis
self - regulating ability to maintain a relatively stable and optimal internal state
constant factors in the internal environment of the body
→ water levels
→ salt concentration
→ pH
→ glucose levels
→ temperature
lungs (homeostatic organ)
co2 + o2 levels in the blood
liver (homeostatic organ)
solute levels in blood
kidneys (homeostatic organs)
water and salt
skin (homeostatic organ)
heat loss and gain
intestines (homeostatic organ)
nutrient and water in the blood
under what condition can cells not absorb glucose in glycogen>
when the glucose blood levels are too high
stimulus (control of body temperature)
change in body temperature
sensor (control of body temperature)
nerve ending in skin
control center (control of body temperature)
hypothalamus brain
effector (control of body temperature)
sweat glands, hair muscle, capillaries, muscles (shivering)
what happens to your glycaemia when you eat
every time you eat glycaemia goes up and will be regulated
glycogen
polymer of glucose
fat cells and glycaemia
fat cells transform glucose into lipids
general cells and glucose
general cells need glucose but they dont store it
chromatin
chromatin is a mixture of DNA and proteins
chromosomes are only visible during cell division
