Cells 9th Grade

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell; Only in plant cells

cell membrane

a selectively permeable layer that surrounds both animal and plant cells; controls what comes in and goes out; consists of a phospholipid bilayer

nucleus

stores hereditary information; surrounded by a nuclear membrane or a nuclear envelope; contains DNA packaged with histones called chromatin until it shortens and thickens to form chromosomes; found in both animal and plant cells

cytoplasm

found in both plant and animal cells; the jellylike fluid that suspends organelles in the cell

mitochondria

found in both plant and animal cells; converts sugar molecules into energy; site of aerobic respiration

Rough Endoplasmic Reticulum

found in both plant and animal cells; has ribosomes attached to it; involved in protein synthesis

ribosomes

found in both plant and animal cells; the site of protein synthesis

chloroplasts

found in plant cells only; captures energy from the sun and uses it as food (photosynthesis)

vacuole

found in both plant and animal cells and it stores food and waste; (Animal cells have a large ________ which stores mainly water)

nuclear membrane

controls what goes in and what comes out of the nucleus

the cell theory

All living things are made up of cells, cells are the basic units of structure and function in living things, new cells are produced from existing cells

Nucleolus

dense structure found inside the nucleus; ribosome production happens here; recognized as the dark portion inside of the nucleus

Smooth Endoplasmic Reticulum

involved in lipid synthesis; detoxification of drugs and poison; breakdown of glycogen in animals

Endoplasmic Reticulum

a series of tubes or channels for transport; connected to the nucleus and lets out in the cytoplasm

Golgi body/apparatus

composed of flattened sacs and small membrane; receives vesicles and their contents from the RER; modifies proteins and repackages them and ships them out to other parts of the cell such as the cell membrane or lysosomes; site of polysaccharide synthesis

Lysosome

contain hydrolytic enzymes that help with digestion of proteins; effective at pH of 5; bond with vacuoles

autolysis

when a cell is injured or dying, the lysosome ruptures to release the contents so it can digest itself; cellicide

microbodies

specialized containers for metabolic reactions

peroxisomes

Contain enzymes that detoxify alcohol; hydrogen peroxide is produced

glyoxysomes

found in fat tissue, converts fat into sugar

cytoskeleton

helps to give support and shape to the cell

cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

prokaryotic cell

cell that does not have a nucleus or other membrane-bound organelles.

eukaryotic cell

cell that has a nucleus and other membrane-bound organelles

Robert Hooke

1. first to observe "small chambers" in cork and call them cells.

Anton van Leeuwenhoek

2. observed tiny living organisms drops of pond water through his simple microscope

Robert Brown

3. discovered cell nucleus and cytoplasmic streaming

Matthias Schlieden

4. concluded that all plants are composed of cells

Theodor Schwann

5. concluded that all animals are made of cells

Rudolph Virchow

6. Discovered all cells come from other cells