[bio] cells part 2 Flashcards
describe the processes in a cell necessary for life
- polypeptide chains are synthesised at the ribosomes and folded at the rough endoplasmic reticulum
- transport vesicles containing substances made by the endoplasmic reticulum pinched off from the endoplasmic reticulum
- transport vesicles then fuse then release their substances into the Golgi apparatus
- these substances are chemically modified and packaged inside the Golgi apparatus
- secretory vesicles containing these modified substances are pinched off from the Golgi apparatus
- the secretory vesicles move towards and fuse with the cell membrane, releasing the substances outside the cell by exocytosis
what are transport vesicles released by
endoplasmic reticulum
what are secretory vesicles released by
Golgi apparatus
describe the formation of lysosomes
- enzyme contents are synthesised on the rough endoplasmic reticulum and transported via transport vesicles to the Golgi apparatus for further processing
- a vesicle containing the processed enzymes buds off from the Golgi apparatus, forming a lysosome
- enzymes have to be kept apart from the rest of the cell or else they would destroy the cell
similarities of typical animal and plant cells
both cells contain:
- cell membrane
- mitochondria
- nucleus
- cytoplasm
differences of typical animal and plant cell
- cell wall
- surrounded by the cell wall in addition to the cell membrane
- cell wall is absent, only surrounded by the cell membrane - chloroplasts
- chloroplasts present in large numbers in photosynthetic cells
- chloroplasts are absent - centrioles
- centrioles are absent
- centrioles are present - vacuoles
- present as a single, large and central vacuole
- vacuoles are small and numerous
what is cell specialisation/differentiation?
multicellular organisms are composed of different types of cells and the structure of the cells is differently adapted to perform a specific function. these cells differ in size and shape and they perform specific functions
examples of specialised cells
- root hair cell
- red blood cell
- muscle cell
adaptation of root hair cell and how it helps
- presence of long and narrow extension
the main function of the root hair cell is to absorb water and mineral salts. the surface area to volume ratio is increased due to the presence of long narrow extension, which increases the rate of diffusion of mineral salts and osmosis.
adaptation of red blood cell and how it helps
- presence of haemoglobin in cytoplasm
haemoglobin combines with oxygen, hence allowing more oxygen to be stored and transported to other body cells - absence of nucleus
absence of nucleus will allow more haemoglobin to be packed in the cell, to bind to more oxygen - biconcave shape
biconcave shape increases surface are to volume ratio to increase rate of diffusion of oxygen and carbon dioxide
adaptation of muscle cell and how it helps
- elongated and cylindrical in shape, contains many nuclei and mitochondria
has numerous mitochondria to provide energy for the contraction of the muscle cell
arrange the terms used in the chapter in increasing order of complexity
- macromolecule
- organelle
- cell
- tissue
- organ
- organ system
definition of macromolecule
a large complex molecule, such as nucleic acids, proteins, carbohydrates, and lipids, with relatively large molecular weight which are made up of small monomers linked together
definition of organelle
a differentiated structure within a cell which performs a specific function
definition of cell
the building blocks of life, simplest units that have all the characteristics of life
