cells Flashcards
(37 cards)
What does a plant cell have that is different to the animal cell
- a cellulose cell wall (with plasmodesmata)
- a vacuole
-chloroplast
What is a plasmodesmata
Channels in membrane for exchanging substances between adjacent cells.
What is the difference between an algal cell and a plant cell
Not much as they contain all the same organelles
However chloroplasts in many algal cells are a different shape and size to plant chloroplasts. Eg some algae have one large chloroplast rather than several smaller ones
All organelles to an animal cell (11)
- cell surface membrane
- rough endoplasmic membrane
- smooth endoplasmic membrane
- nucleolus
- nucleus
- lysosome
- ribosome
- nuclear envelope
- Golgi apparatus
- cytoplasm
- mitochondrion
Fungal cells differences to plant cell
Their cell wall is made out of chitin, not cellulose
They don’t have chloroplast because they don’t photosynthesise
Organelles in all eukaryotic cells (10)
- cell surface membrane
- rough endoplasmic reticulum
- smooth endoplasmic reticulum
- nucleolus
- nucleus
- nuclear envelope
- ribosome
- cytoplasm
- mitochondrion
-Golgi apparatus
what is a Golgi apparatus
a group of fluid-filled membrane bound sacs, vesicles are often seen on the edge of the sacs
(PACKAGING CENTRE)
it receives many molecules and can determine where to send them (eg to the membrane to be secreted)
its function is to process and package new lipids and proteins that have been received from the vesicles from the endoplasmic reticulum. also determines where to send molecules
it also makes lysosomes.
what is a golgi vesicle
small fluid filled membrane bound sack in the cytoplasm and produced by the Golgi apparatus
function: stores lipids and proteins made by the golgi apparatus and transports them out of the cell
what is a nucleus
large organelle surrounded by a nuclear envelope which contains many pores (which allow substances eg RNA to move between nucleus and cytoplasm.
nucleus contains chromosomes and one or more structures called a nucleolus
function: controls the cells activities (by controlling the transcription of DNA.
structure of the nucleus
nucleus contains NUCLEOLUS (which is where ribosomes are made)
nucleus is surrounded by nuclear envelope
(which has pours in to allows substances like RNA to transport in and out the nucleus
nucleus and nucleolus
inside the nucleus there is a nucleolus which is where ribosomes can be produced
also attached to the membrane of the nucleus is endoplasmic reticulum
cell surface membrane (plasma membrane)
mainly made of lipids and proteins.
function: regulates the movement of substances into and out of the cell. SEMI PERMEABLE, keeps cell stable so keeps homeostasis
also has receptor molecules on it, which allow it to respond to chemicals like hormones
what is a lysome
a round organelle surrounded by a membrane with no clear internal structure, its a type of golgi vesicle
function: contains digestive enzyme called lysozymes, can be used to digest invading cells or break down worn out components of the cell.
ribosome
a very small organelle that floats free in the cytoplasm made up of proteins and RNA, not surrounded by a membrane
function: the site where proteins are made
cell wall
a rigid structure that surrounds plant, algae, and fungi
plants= cellulose
algae=chitin
prokaryotic=murien
function: supports cell and prevents them from changing shape
cell vacuole
contains cell sap (weak solution of sugar and salts) surrounding membrane is called the tonoplast
function: helps to maintain pressure inside the cell and keep the cell rigid, this stops the plant wilting
also involved in isolation of unwanted chemicals inside cell.
endoplasmic reticulum
attached to the nuclear membrane
there are:
Rough Endoplasmic Reticulum (RER)
Smooth Endoplasmic Recticulum (SER)
both involved in transport of their molecules around
rough endoplasmic reticulum (attached to the nuclear membrane)
a system of membranes enclosing a fluid-filled space, the surface is covered with ribosomes
function: folds and processes proteins that have been made at the ribosomes. it also transports the proteins out the ER, it can be sent out and away the ER in vesicles
smooth endoplasmic reticulum
similar to rough endoplasmic reticulum but with no ribosomes
function: synthesises and processes lipids, also involved in detoxification.
mitochondrion
oval shaped with a double membrane.
inner one folds over to form a structure called cristae, inside the mitochondrion there is the matrix which contains enzymes involved in respiration
function: site of aerobic respiration which produces ATP which is a common energy source.
chloroplast
small structure found in plant and algae cells,
surrounded by a double membrane
has membranes inside called thylakoid membranes
these thylakoid membranes are stacked up in some parts to from grana
grana are linked by lamellae (thin pieces of thylakoid membrane
function: site where photosynthesis takes place
some parts take place in grana and other in the stroma (thick fluid)
what are the three points of modern cell theory
- the cell is the smallest living unit in any organism
- all living things are made of cells
3.all cells come from from other pre-existing cells
two types of prokaryotes
- archaea
2.bacteria
