Cell Structures (Part 2) Flashcards
(Again) What are cells?
They sustain life by performing the tasks essential for the cell to function. Cells are the smallest functional unit of life. The things that make them up aren’t.
What are the tasks necessary for a cell to function?
a) obtain food and energy
b) convert energy (photosynthesis)
c) construct and maintain the molecules that make up the cells
d) carry out chemical reactions
e) eliminate waste and toxins
f) reproduce
What are organelles?
The internal cell parts carry out specific functions.
What are prokaryotes?
One-celled organisms that lack a membrane-based nucleus and organelles.
- Are the most abundant on Earth
- DNA is found bundled in the middle
Example: most bacteria, algae
*before nucleus
What are eukaryotes?
(grade 10 is more important)
Cells with a complex internal structure, including a membrane-bound nucleus and organelles.
Example: animals, plants, fungi, protists, some bacteria
*true nucleus
What is the cell membrane/plasma membrane?
- Protective barrier that separates the cell interior from the environment
- Keeps wanted materials inside and unwanted materials out, and allows for transport of needed materials.
Example: border control - Composed of a phospholipid bilayer with some proteins jammed into it
O
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*protective barrier
What is cytoplasm?
- Jelly-like cell contents that support the other organelles
- 70% water
- Acts more like a thick solution
*“empty space”
look like nothing
What are vesicles?
- Small membrane sacs that store and transport materials in and out of the cell
- Pinched off cell-membrane; also made out of phospholipid bilayer
*“bubbles of things I can put stuff into” “organization” “can store or move stuff” “mostly transportation”
look like bubbles
What are lysosomes?
Vesicles + digestive enzymes
- Still are bubbles of membrane
- Can fuse with other vesicles to digest food particles, kill bacteria infections, and break down own cell parts
- Can be used for cell suicide
*“suicide sacs”
look like sacs
What is the nucleus?
- Directs cell activities
- Contains almost all of your DNA (instructions)
- Materials enter/leave the nucleus through NUCLEAR PORES IN NUCLEAR MEMBRANES
- Also produce copies of your DNA to use to make cell products (can’t afford to lose original DNA)
*control panel
very big center with holes
What is the nucleolus?
- The dense region of the nucleus where ribosomes are produced
- Spot where DNA is being actively translated
*ribosome producer
the dense part of the nucleus
What are ribosomes?
Dense granules that may be found attached to the Rough Endoplasmic Reticulum or freely floating to the cytoplasm
- Site of protein synthesis, where amino acids are assembled into proteins according to the information stored in DNA.
synthesizes proteins
*protein makers—chefs with instructions on making the food
small flat spheres
What is the endoplasmic reticulum (ER)
*made of a phospholipid bilayer, just like cell membrane, vesicles, and nuclear membrane
- Network of continuous tubes branching from the nucleus throughout the cell though which materials can be transported
a) Rough ER connected paths from nucleus, with dots over
Has ribosomes on the surface
- Packages/makes protein into vesicles for transport
where proteins are made
b) Smooth ER connected paths from nucleus, no dots
No ribosomes on the surface
- Produces lipids (including the phospholipids)
where lipids and synthesizes and trasported
*Transportation routes
What is the Golgi apparatus?
- Flat, non-connected disc (pancake) shaped sacs that sort, modify, and replace molecules sent from the ER.
- The needed materials are pinched off into vesicles and sent to other parts of the cell or to the cell membrane for transport out
*sorts, makes sure good (from ER) and repackages molecules into vesicle, “post office” (to out, vacuoles, mitoc.)
*produces lysosomes
looks like stacked pancakes
What is the Mitochondria?
Bean-shaped organelle with folded inner membranes
- Site of cellular respiration, where chemical energy stored in food (glucose) is converted into useable energy (ATP)
- ATP: adenosine triphosphate
*powerhouse of the cell, food into ATP (chemical energy)
Cellular Respiration: C6H1206 (aq) + 6O2 (g) -> 6CO2 (g) + 6H2O (l) + ATP energy
looks like a bean with folded inner membranes
