Transcript Diapositiva 1

WHAT IS THIS??
ANY IDEAS????
HAVE YOU
EVER SEEN
THESE??
I´M SURE YOU
KNOW WHAT IS
THIS…
ALIENS???
MAY BE
PARTS OF
YOUR
BODY?
AMAZING… DON´T YOU
THINK SO?
NOW… LET´S ANSWER
SOME QUESTIONS
CELL THEORY
The invention of the microscope in the late 1500s
revealed to early scientists a whole new world of tiny
cells. Most cells are so small that they cannot be seen
without a microscope. The discoveries of scientists
from the 1600s through the 1800s led to the cell
theory, which is a unifying concept of biology. The cell
theory has three major principles:
• All organisms are made of cells.
• All existing cells are produced by other living cells.
• The cell is the most basic unit of life.
All cells can be divided into two major groups: prokaryotic
cells or eukaryotic cells. The main differences between
the two kinds of cells are in their structure:
• Eukaryotic cells have a nucleus defined by a membrane,
while prokaryotic cells have no nucleus.
• In eukaryotic cells, the DNA, or genetic information, is
found in the nucleus. In prokaryotic cells, the DNA is
found in the cytoplasm, the jellylike substance
that fills both types of cells.
• Eukaryotic cells have organelles, structures that
perform jobs for a cell. Most organelles are surrounded
by membranes. Prokaryotic cells do not have organelles
surrounded by membranes.
Prokaryotic cells make up organisms called
prokaryotes. All prokaryotes are tiny and
consist of single cells. Bacteria are prokaryotic
cells. Eukaryotic cells make up eukaryotes.
You are a eukaryote, as are plants and some
types of single-celled organisms. All
multicellular organisms, or organisms that
have many cells, are eukaryotes.
The questions
1. What is the smallest, most basic unit of life? ____________________________________________
2. Where is the DNA in a prokaryote? in a eukaryote?
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3. Why would you need a microscope to see a prokaryotic organism?
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4. A friend tells you he read somewhere that rotting garbage can turn into maggots, which are fly larvae,
and the maggots then can grow into adult flies. What part of the cell theory could you use to refute
his claim?
MAIN IDEA:
Prokaryotic cells lack a nucleus
and most internal structures of eukaryotic
cells.
In the top left side of the Y shape below, write
the characteristics of eukaryotic cells. In the
top right side of the Y shape below, write the
characteristics of prokaryotic cells. At the
bottom of the Y shape below, write the
characteristics that both kinds of cells have in
common.
HOME- WORK
MAIN IDEA:
Early studies led to the development of the cell theory.
In a phrase, tell what each scientist did to help develop the cell theory.
1. Hooke
2. Leeuwenhoek
3. Schwann
4. Virchow
What are the three parts of the cell theory?
ANIMAL CELL
REMEMBER SOMETHING ABOUT THE PARTS OF
THE CELL?
AS WELL AS YOU HAVE ORGANS THE CELLS HAVE
SOMETHING THAT WE CALL
ORGANELLES
THIS WAS AN ANIMAL CELL… PAY CLOSE
ATTENTION TO IT. DO YOU REMEMBER
SOME OF ITS PARTS?
MITO…..
LYSO……
NUC………….
CELL MEM………..
RIBO……………
NOW, LET´S START WITH THE COVERING
LAYER OF THE CELL. THE NAME IS
DIFFERENT FOR PLANTS AND ANIMALS.
IN ANIMAL CELLS THE NAME IS CELLULAR
MEMBRANE
IN VEGETABLE CELLS THE NAME IS CELL
WALL
WHAT DO YOU THINK THAT WAS?
ANIMAL CELL????
OR
CELL WALL????
WHAT DO YOU THINK THAT WAS?
ANIMAL CELL????
OR
CELL WALL????
LOOK THE
DIFFERENCE
BETWEEN THEM, THE
FOLLOWING IMAGES
ARE CELL WALLS
NOW…
COMPARE
THEY LOOK PRETTY DIFFERENT,
DON´T YOU THINK SO?
LET´S LIST THE MAIN DIFFERENCES
BETWEEN THEM
(BY THE WAY, AT THIS MOMENT YOU
HAVE TO COPY ON YOUR NOTEBOOK)
WELL, THAT WAS THE CELL MEMBRANE Vs THE CELL WALL, NOW,
ARE YOU READY TO TAKE A QUIZ?
QUESTION:
1. WHY DO YOU THINK CELL WALLS ARE THICKER THAN CELL
MEMBRANES?
A. BECAUSE IT WOULD BE MUCH MORE DIFFICULT FOR
HERBIVORES TO EAT THEM
B. BECAUSE THE MORE THICKER IT IS MORE NUTRIENTS IT
HAVE
C. BECAUSE THAT IS THE WAY NATURE IS AND THERE ARE NO
EXPLAINATIONS
D. BECAUSE IF SOMETHING IS SOFT AS THE CELL MEMBRANE
IT IS HARDER TO EAT IT, INSTEAD, IF IT IS HARD AND STRONG
AS THE CELL WALL IT WOULD BE EASIER TO EAT IT… SOUND
LOGICAL DON´T YOU THINK SO.
REVIEW ABOUT CELL WALL AND CELL MEMBRANE.
The main function of the cell wall and the cell membrane is to give support and allow
the movement of substances like water and nutrients in and out the cell.
CELL WALL
CELL MEMBRANE
1. Is thicker than the cell membrane.
2. It is rich in cellulose
3. It is harder to break it
1. It is softer than cell wall.
2. It is not rich in cellulose
3. It is much more simple to break it
All these reasons make the cell wall
harder to eat and that´s why
sometimes we have to cook the
vegetables we eat during long
periods of time.
It is even har for the chemical juices of
your stomach to digest the cell wall
and cooking and heating we help
this process to be much more
efficient.
All these reasons make the cell
membrane easier to break and
digest, have you ever eat sushi, it is
made up of raw fish, and when we
eat it we don´t have any digestion
problems
THE CYTOPLASM
*WHAT IS IT?
*WHAT IS ITS FUNCTION?
SUPPOSE THIS IS A CELL, THE CYTOPLASM WOULD BE:
THE BLUE PART REPRESENT THE CYTOPLASM, ITS
FUNCTION IS TO HOLD THE OTHER ORGANELLES
PRESENT IN THE CELL.
THE CYTOPLASM IS MADE UP OF SUGARS, SALTS,
PROTEINS, AMINOACIDS AMONG OTHERS, AND IT IS
ALSO MADE UP OF A NET OF PROTEIN FIBERS CALLED
THE CYTOSKELETON.
ALL THESE THINGS TOGETHER MAKE A STRONG,
RESISTANT SPACE FOR THE ORGANELLES HANG ON,
ORGANELLES ARE NOT JUST FLOTING, THEY ARE
HOLDED ON TO THE FIBERS OF THE CYTOSKELETON.
The nucleus is one of the most visible
parts of cells, it is made up by the
nuclear membrane (it separates the
nucleus of the rest of the cell), the
nucleolus (it is important for the
ribosome formation) and the chromatin
(which is made up of DNA and during
cell reproduction forms the
chromosomes)
Vacuoles are present in animal and
vegetable cells, they are bubble like
structures which function is to store water,
sugars, salts and pigments
Ribosomes can be anywhere in
the cytoplasm or attached to the
rough endoplasmic reticulum, the
principal function of ribosomes is
to create proteins and proteins is
the chemical compound that forms
your muscles and almost every
part of your body