topic 2 - eukaryotic cells and organelles Flashcards
cgp (topic 2A) 26 - 29
what are eukaryotic organisms
complex cells that contain a nucleus and organelles enclosed by a plasma membrane
four examples of eukaryotic cells
animal cells, plant cells, all cells in algae and fungi
name 11 organelles contained in an animal cell
(1) plasma (cell surface) membrane
(2) rough endoplasmic reticulum
(3) smooth endoplasmic reticulum
(4) nucleus
(5) nucleolus
(6) nuclear envelope
(7) lysosome
(8) ribosome
(9) cytoplasm
(10) mitochonrion
(11) golgi apparatus
do plant cells have the same organelles as animal cells
plant cells have all the same organelles as animal cells but a few added extra
name 14 organelles contained in a plant cell
(1) plasma (cell surface) membrane
(2) rough endoplasmic reticulum
(3) smooth endoplasmic reticulum
(4) nucleus
(5) nucleolus
(6) nuclear envelope
(7) lysosome
(8) ribosome
(9) cytoplasm
(10) mitochonrion
(11) golgi apparatus
(12) cellulose cell wall
(13) vacuole
(14) chloroplast
how are algae a lot like plant cells
they have all the same organelles including a cell wall and chloroplast
what are the two key differences that differenciates fungal cells from plant cells
(1) their cell walls are made of chitin, not cellulose
(2) they don’t have chloroplasts (as they don’t photosynthesise)
what are organelles
subcellular structures that exist within most cell types that has a very specific function or job
describe the cell surface (plasma) membrane
the membrane found on the surface of animal cells and just inside the cell wall of other cells - it’s made mainly of lipids and proteins
what is the function of a cell surface (plasma) membrane
regulates the movement of substances into and out of the cell - it also has receptor molecules on it which allows it to respond to chemicals like hormones
describe the nucleus
a large organelle surrounded by a nuclear envelope (double membrane) which contains many pores - the nucleus contains chromosomes (which are made from protein bound linear DNA) and one or more structures called nucleolus
what are the functions of a nucleus
controls the cell’s activities (by controlling the transcription of DNA) - DNA contains instructions to make proteins - the pores allow substances to move between the nucleus and the cytoplasm - the nucleolus makes ribosomes
describe the mitochondrion
they’re usually oval shaped - they have a double membrane - the inner one is folded to form structures called cristae - inside is the matrix which contains enzymes involved in respiration
what is the function if mitochondrion
the site of aerobic respiration, where ATP is produced - they’re found in large numbers in cells that are very active and require a lot of energy
describe a chloroplast
a small, flattened structure found in plant and algal cells - it’s surrounded by a double membrane, and also has membranes inside called thylakoid membranes - these membranes are stacked up in some parts of the chloroplast to form grana - grana are linked together by lamellae - thin, flat pieces of thylakoid membrane
what are the functions of a chloroplast
the site where photosynthesis takes place - some parts of photosynthesis happen in the grana, and other parts happen in the stroma (a thick fluid found in chloroplasts)
describe the golgi apparatus
a group of fluid filled, membrane bound flattened sacs - vesicles are often seen at the edges of the sacs
what are the functions of the golgi apparatus
it processes and packages new lipids and proteins- it also makes lysosomes
describe the golgi vesicles
a small fluid filled sac in the cytoplasm, surrounded by a membrane and produced by the golgi apparatus
what are the functions of the golgi vesicle
it stores lipids and proteins made by the golgi apparatus and transports them out of the cell (via the cell surface membrane)
describe a lysosome
a round organelle surrounded by a membrane with no clear internal structure- it’s a type of golgi vesicles
what’s the functions of a lysosome
contains digestive enzymes called lysozymes - these are kept separate from the cytoplasm by the surrounding membrane and can be used to digest invading cells or to break down worn out components of the cell
describe a ribosome
a very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum - it’s made up of proteins and RNA - it’s not surrounded by a membrane
what is the function of a ribosome
the site where proteins are made
describe a rough endoplasmic reticulum (RER)
a system of membranes enclosing a fluid filled space - the surface is covered with ribosomes
what is the function of the rough endoplasmic reticulum (RER)
folds and processes proteins that have been made at the ribosomes
describe a smooth endoplasmic reticulum (SER)
simulate to rough endoplasmic reticulum, but with no ribosome
what is the function of a smooth endoplasmic reticulum (SER)
it synthesises and processes lipids and carbohydrates
describe a cell wall
a rigid structure that surrounds cells in plants, algae and fungi - in plants and algae it’s made mainly of the carbohydrate cellulose - in fungi it’s made of chitin
what are the functions of a cell wall
it supports cells and prevents them from changing shape
describe a cell vacuole
a membrane bound organelle found in the cytoplasm of plant cells - it contains cell sap - a weak solution of sugar and salts - the surrounding membrane is called the tonoplast
what are the functions of a cell vacuole
helps to maintain pressure inside the cell and keep the cell rigid - this stops plants wilting - also involved in the isolation of unwanted chemicals inside the cell
what is a specialised cell
cells with unique structures and functions in the body
what are 3 ways epithelial cells in the small intestine specialised to absorb food efficiently
(1) the walls of the small intestine have lots of finger like projections called villi - these increase surface area for absorption
(2) epithelial cells on the surface of the villi have folds in their cell surface membranes called microvilli - microvilli increase surface area even more
(3) they also have lots of mitochondria - to provide energy for the transport of digested food molecules into the cell
how are specialised cells organised
into tissues, organs and organ system
what are specialised cells grouped together to form in multicellular eukaryotic organisms
tissues
what is a tissue
a group of cells working together to perform a particular function
how what do epithelial cells make up
epithelial tissues
what three tissues work together to form the stomach
epithelial tissue, muscular tissue, grandular tissue
what is the digestive system
an organ system made up of all the organs involved in the digestion of food including the small intestine, large intestine and liver
