LOOKING INSIDE CELLS

Chapter 4, Section 36th Grade Text

TYPE OF CELLS• PROKARYOTES – Cells that have a cell wall

and cell membrane but lack an organized nucleus. Example is bacteria cell.

TYPE OF CELLS• EUKARYOTES – Cells that contain a defined

nucleus and a variety of organelles.Examples are animal cells and plant cells.

ANIMAL CELLS• Animal cells (and plant and bacteria cells) contain within them tiny cell

structures call organelles that carry out specific functions within the cell. Examples of organelles are ribosomes, mitochondria, and endoplasmic reticulum.

organelles

• is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer.

CELL MEMBRANEFor animal cells, the cell membrane forms the outside boundary that separates the cell from its environment. Its structure is essentially a double layer of fat with embedded proteins. Its main function is to control what substances come into and out of the cell.

CELL MEMBRANE

Draw the Nucleus and label it!

NUCLEUS• The nucleus is a large oval

structure that acts as the “brain” of the cell, controlling all of the cell’s activities.

• It is made up of the nuclear membrane, chromatin and nucleolus.

NUCLEAR MEMBRANE• The nuclear membrane,

like the cell membrane, is essentially a double layer of fat.

• It’s function is to protect the nucleus, and to allow materials to pass in and out of the nucleus through small openings (pores) in the membrane.

chromatin• Contains in the nucleus• consisting of long strands

of DNA (nucleic acid). When the cell is in resting stage, the chromatin is relaxed and when the cell is going to divide, chromatin condenses and forms what is known as “chromosome”during cell division

CHROMOSOMES• The nucleus contains thin strands of genetic material called chromatin.

When the cell begins to divide, the chromatin strands coil and condense to form structures called chromosomes.

NUCLEOLUS• a non-membrane bound

structure found inside the nucleus.

• Function made ribosomes.

CYTOPLASM• Is a thick, clear, gel-

like fluid found between the cell membrane and the nucleus.

• Most cell activities take place in the cytoplasm

• Is where the Cell organelles are found “floating” in the cytoplasm.

MITOCHONDRIA• rod-shaped organelles

called the “power-houses”• produce most of the

energy the cell needs to carry out its functions.

• Muscle cells and other very active cells have large numbers (1000s) of mitochondria. Less active cells might have only one mitochondria.

ENDOPLASMIC RETICULUM• Is a maze of

passageways• Function carry proteins

and other materials from one part of the cell to another.

Smooth ENDOPLASMIC RETICULUM

• Is smooth… no presence of ribosomes.

• is involved in lipid synthesis and steroid synthesis.

• It is also involved in drug detoxification.

Rough ENDOPLASMIC RETICULUM• surface of the

membrane of RER is studded with ribosomes (another type of organelle)

• function of RER is the synthesis and manufacture of proteins.

RIBOSOMES• Ribosomes are small,

grain-like bodies either attached to the endoplasmic reticulum or free floating in the cytoplasm.

• Ribosomes are factories that produce proteins.

• These proteins are passed to the ER, then transported to the Golgi Bodies.

RIBOSOMES

GOLGI BODIES

• structures that look like a flattened collection of sacs and tubes that serve as the cells “mail-room”.

• Function: receive proteins from the ER, package them, and deliver them either to other parts of the cells, or release them outside the cell.

GOLGI BODIES

LYSOSOMES

• small, round, membrane enclosed.

• Functions: break down food particles and old cell parts. Then the substances released can be recycled and used to build new parts.

VACUOLES• membrane-bound organelles• Functions: store water, food, and other materials needed by

the cells but they can also contain waste products.• Vacuoles are more prominent in plant cells, and typically

occupy more than 30% (and up to 80%) of a plant cell’s volume.

LYSOSOMES & VACUOLES

Cells organelles song

• Mr. W cells song with all the animal cell organelles

PLANT CELLS

PLANT CELLS

CELL WALL• The cell wall is a rigid

layer of non-living material that surrounds the cells of plants. It is made of a tough, flexible material called cellulose (Wood contains lots of cellulose.) The cell wall functions to protect and support the cell.

CHLOROPLASTS• Chloroplasts are large green organelles that function to capture

energy from sunlight and use it to produce food for the cell. Remember: 6CO2 + 6H2O C6H12O6 + 6O2

• Mr. W cells song with all the animal cell organelles and plants

• cell rap• Interactive cells