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Flashcards in Biology - Organelles Deck (20):
1

Organelles

A specialized compartment within a cell that carries out a specific function

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Cell membrane

- Acts as a barrier between intracellular fluid + extracellular fluid

- Controls what enters/exits the cell

- "semi-permeable membrane"

3

Cell wall

- Made of cellulose that makes wall tough and strong

- Provides structural support + protection

4

Nucleus

- Surrounded by double membrane 

- Controls the activities of the cell

- Contains genetic info (DNA in chromosomes)

5

Nuclear membrane

- Encloses the genetic info (DNA)

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Cytoplasm

- Area between cell membrane + nuclear membrane

- Contains substances (enzymes, ATP) until cell needs it

- Organelles are suspended

7

Cytosol

Liquid that makes up cytoplasm which contains water, ions, and other small molecules

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DNA

- Found in nucleus entangled as chromatin

- Makes up genetic code of cell

- Is the hereditary information

9

Nucleolus

- Site at which ribosomes are made

- No membrane

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Ribosomes

- Small, dark, spherical organelles

- Attached to membranes of RER or float freely in cytoplasm

- Makes proteins

11

Endoplasmic reticulum

- Series of interconnected tubes that are formed by membranes

- Can be continuous with the nucleus membrane

RER; ribosomes attached + transports proteins that are made by ribosomes throughout cell

SER; makes lipids (fat), storage site for calcium ions

12

Golgi bodies

- Loosely stacked sacs of membrane

- Often interconnected with ER

- Receive, modify, and transport protein

- Secrete mucus

13

Vacuole

- Fluid filled spaces containing water and dissolved molecules

- Surrounded by single membrane called tonoplast

- Store food particles or waste

 

- In plants: provide support and storage space for water and starch

The vacuole in plant cells hold water, creating turgor pressure against the cell

 

14

Mitochondria

- Rod shaped, 1-3 micrometers long

- Has double membrane

- Inner membrane is folded projections called cristae

- Fluid inside is the matrix

- Breaks down large macromolecules to release stored energy in a process called cellular respiration (glucose + O2 = CO2 + H2O + energy) which is converted to an easily usable form (ATP)

15

Chloroplasts

- Oval, 5-10 micrometers long

- Has a double membrane + own DNA and ribosomes

- The # of chloroplasts vary (1-200) per cell

- Chrlorophyll (green pigment) in thylakoids trap sunlight and uses it to make glucose in photosynthesis (CO2 + H2O = glucose + O2)

 

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16

Lysosomes

- Found in both plant and animal cells 

- Spherical organelles that are bound by single membrane

- Contain enzymes (type of protein) derived from RER

 

- Digest food molecules (food to cell to vacuole which joins up with lysosome)

- Destroy harmful chemicals that enter the cell by engulfing them

- When cell is old and doesn't function, lysosomes act as suicide bags and breakdown, releasing their digestive enzymes into cytoplasm

- Enzymes are also used to destroy old + damaged organelles

17

Centrioles

- Present in animal cells

- Short cylinders that occur in pairs at right angles called centrosome

- During mitosis; centrioles in centrosome travel to opposite poles of cell

- Also associated with produciton of cilia and flagella 

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Animal cell?

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Plant Cell?

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20

Secretory Vesicles

Once sugar and fat molecules is added to protein, they collect in sacs that pinch off from the golgi; they remain in cytoplasm or move to cell membrane to be expelled