Cells Flashcards
have no true nucleus
prokaryotes
Where can the DNA be found in prokaryotes?
Nucleoid
have nuclues
Eukaryote
- spherical structure found in the cell’s nucleus whose primary function is to produce and assemble the cell’s ribosomes
- dark-staining body
Nucleolus
Who examined a thin slice of cork tissue
Robert Hooke (1665)
What did Robert Hooke observe in the thin slice of cork tissue?
honeycombed compartments
What did Robert Hooke called those honeycombed compartments he observed?
cellulae (small rooms)
Who proposed the first two statements of the cell theory in 1838-1839?
Matthias Schleiden and Theodor Schwann
concluded that all plant parts are made of cells
Matthias Schleiden
concluded that all animal tissues are made of cells
Theodor Schwann
What are the three (3) principles of cell theory?
- All organisms are composed of one or more cells
- Cells are the smallest living things
- Cells arise only by division of a previously existing cell
self-organized, endogenously ordered, spherical collection of lipids proposed as a stepping-stone toward the origin of life.
Protocell
What do plant cells have that animal cells do not have?
- cell wall
- chloroplasts
- large central vacuole
Cell wall are made up of __.
cellulose (most abundant carbohydrate)
Organelles responsible for photosynthesis
chloroplasts
internal membranes of chloroplasts and cyanobacteria that provide the platform for the light reactions of photosynthesis
Thylakoid
- stores nutrients and water on which a cell can rely for its survival.
- also stores wastes from the cell to prevent contamination
Large central vacuole
What do animal cells have that plant cells do not have?
- lysosomes
- centrioles
- flagella (though present in some plant sperm)
- membrane-bound cell organelle that contains digestive enzymes
- break down excess or worn-out cell parts
- may be used to destroy invading viruses and bacteria
Lysosomes
help to arrange the microtubules that move chromosomes during cell division
Centrioles
microscopic whip-like structure that helps to propel a cell through liquids
flagella
- provides pigmentation to skin, eyes, and hair.
- absorbs harmful UV (ultraviolet) rays and protects cells from sun damage
Melanin
- command center of the cell
- directs all of the cell’s activities
Nucleus
What does the nucleus store?
hereditary information
What surrounds the nucleus?
Nuclear envelope (has pores)
- large complex of proteins that allows small molecules and ions to freely pass, or diffuse, into or out of the nucleus
Nuclear pore
extensive system of interior membranes that divides the cell into compartments
Endomembrane System
What does the endomembrane system consists of?
- Endoplasmic Reticulum
- Golgi Complex
- Lysosomes
- Peroxisomes
internal membrane system creating channels and membrane-bound vesicles
Endoplasmic Reticulum (ER)
What are the two (2) distinct regions that the Endoplasmic Reticulum consists?
- Rough Endoplasmic Reticulum (ER)
- Smooth Endoplasmic Reticulum (ER)
- studded with ribosomes
- involved in protein synthesis
Rough Endoplasmic Reticulum (ER)
- embedded with enzymes
- involved in lipid and carbohydrate synthesis
Smooth Endoplasmic Reticulum (ER)
Where does the ER transport the molecules it synthesizes to?
Golgi Complex
- flattened stack of membranes that are scattered throughout the cytoplasm
- collects, packages, modifies, and distributes molecules
Golgi complex
carry cargo from the endoplasmic reticulum to the Golgi
Transport vesicles
- consists of the materials that have to be excreted from the cell
- these may carry soluble proteins, peptides, or neurotransmitters
Secretory Vesicles
- contain enzymes that break down macromolecules
- arise from the Golgi complex
Lysosomes
The lysosomes function in intracellular digestion of:
- worn-out cellular components
- substances taken into cells
- resulting material is then recycled
- arise from the Endoplasmic reticulum
- contain two (2) sets of enzymes
Peroxisomes
What are the two (2) sets of enzymes that are found in peroxisomes?
- One set is found in plants
- Other set is found in animals
What does the enzyme contained in peroxisomes that are found in plants do?
converts fats to sugars
What does the enzyme contained in peroxisomes that are found in animals do?
detoxifies various harmful molecules
What are the two (2) organelles that contain DNA?
- Mitochondria
- Chloroplasts
Powerhouse of the cell
Mitochondria
How do mitochondria extract energy from organic molecules?
Through oxidative metabolism
process by which ATP synthesis is coupled to the movement of electrons through the mitochondrial electron transport chain and the associated consumption of oxygen
Oxidative phosphorylation
Like bacteria, mitochondria:
- Possess circular DNA (plasmid)
- Divide by simple fission