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When we differentiate between animals and plants cells what are some of the major characteristics you could look for in a plant cell
that would tell you that it is a plant cell and not an animal cell
there a couple of things on this diagram that should stand out to you
that look very different compared to animal cells
when we draw animal cells, we always draw them as round
with structures on the inside
the organelles
now many of the organelles with our animal cell will be the same as the ones here
we will have mitochondria
kinda shaped like kidney bean with lots of surface area on the inside that we use for cell respiration
we will have Golgi (protein production)
ribosomes
microtubules
in our animal cells as well
we will of course have a nucleus
and endoplasmic reticulum (ER)
we will have all these things inside an animal cell
Right? we will have other things inside an animal cell as well. something called a lysozyme
LYSOZYME
remember those were garbage trucks
and recycle nutrients
but we don't see those here
the other thing that we typically see is a very flexible outer membrane to our animal cell
right?
we don't see that here
instead
we see things like chloroplast
while there's no chloroplast in my animal cell, And we know that chloroplasts are a distinguishing feature
plant cells and that they are needed and photosynthesis
we have the central vacuole.
This big blob in the middle of our plant cell
in this case we talk about our central vacuole used associated with water storage, nutrient storage
and they actually will take the place of our lysozymes, so they also act as a garbage truck
plasmodesmata this is another weird one
associated just with plants
we see this is the connection between two plants cells kinda looks like a button here -- right?
well what we're actually seeing is the overlapping of the plasma membrane between two plant cells so the plasma membrane still
exists of course in plant cells helps to regulate what comes in and out
and so what we see is actually an overlap of of that material to hold the cells together and make them rigid
well -- what else is on the outside here?? the outside of our plant cells course has a cell wall
in plants we look at that primarily being composed of cellulose
we saw cell walls and prokaryotes (bacteria) as well. different kind of composition but the cellulose is
important in our cell walls it's what we equate with dietary fiber
you cannot digest cellulose -- what we look for is its job
in digestion to help you actually clean out your system
so those are the major components that we see here
we'd still have cytoplasm filling the inside of the cell and so on but just like you this the basic
cell structure for plant we can certainly look at other structures
depending on the exact cell type that we see in our plants
so we want to look at actually five major types of plants cells and those five major types of plants cells
and listed out for you
right here they have some odd names associated with them so few of the spellings
here. parenchyme cells, or PA - REN- KA - MA depending on how you pronounce it. colenchyme - or COL - EN - KA -MA.
Sclerenchyma, or SCLAR - EN - KA - MA. water conducting cells that we've already talked about as being vascular tissue
and food conducting cells that are also known as vascular
tissue and build vascular tissue so we said our water conducting cells are actually xylem
and our food conducting cells are phloem
we saw that in our tissue discussion
but when we look at plants cell types we have to think the cells will make up the tissues right?? That's the job of the cells is to build tissues
so ..since we're familiar with the vascular
cells and welcome back to those again later I wanna focus instead on our parenchyme, colenchyme, and sclerenchyme
parenchyme cells and are actually the most abundant cells that we see in the cells structures
and in the plant structures so we see these throughout the majority of the plant they tend to be very thin cell walled. this will be one of
our identifying characteristics of a cell type is how thick that cell wall is and then what's their job ??
well the job of a parenchyme cell is to do all of the metabolic work of the plant
so anything associated with energy
so in that case were to be talking about photosynthesis
cell respiration -- right? all of these things. now we also have to think about the fact that parenchyme
cells if they are involve the metabolic processes will also be involved in any plant growth
here they show a picture of of parenchyme cells storing starch again a great
task for them because the cell walls are thin and they can get a lot of starch stored on the inside
these are your collenchyme cells
notice that has a fairly thick cell wall in this image
on the right the dark space that surrounds the white are actually the cell walls
the open white spaces are the inside of the cells so the cell walls
cell walls surrounding the outside
so you see that they are thicker. They are not necessarily even and the reason for this is
they actually have a primary cell wall and a secondary cell wall associated with them this
gives them more support so they are a stronger cell than the parenchymes that we just talked about
but they still are flexible so we look at collenchyme cells as being present in
areas of growth
so any place the plant is growing you're going to see a lot of the cells to help give it support
the last type of plant cell that we're going to talk about is the sclerenchyme cells so these are actually two different types of cells
fibers and sclerids. so when we look at these two different types they will have different functions in the plants and we are going to use
all of the cells in our future discussions of plants to talk about their major functions and where they will actually fit in
to what's going on with our with our plant in a given timeframe in and how it's actually working so
the one last image and one show you that we will come back to when we talk about
our vascular tissue more is this cross section of the stem or cross section of a vascular bundle showing you the difference between
xylem and the phloem and we will get in to more about the structures associated with
xylem and the phloem later on but when we look at these sieve tubes these are associated with food
movement so sugar
Which cells in the vascular tissue
or which component of the vascular bundle did we say was primarily associated with food??