Chapter 3: The Cell Flashcards Preview

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Flashcards in Chapter 3: The Cell Deck (50):
1

Theory of Endosymbiosis

The theory that eukaryotic cells emerged when chloroplasts and mitochondria took residence inside larger cells.

2

Modern Cell Theory

Theory that all cells arise from preexisting cells.

3

All cells have...

a plasma membrane, cytosol, and DNA of some sort.

4

Prokaryotic Cells

Simple cells with no nucleus or organelles, like bacteria.

These types of cells have a nucleic region (where the DNA is located) instead of an enclosed nucleus.

5

Eukaryotic cells

Have a nucleus bound by a double membrane, as well as organelles.

6

Surface Area to Volume

Surface area increases slower than volume (look at the formulas for surface area and volume for different shapes).

Thus, the surface area limits the amount of stuff that can enter and exit the cell.

7

Nucleolus

Located within the nucleus, and controls ribosome and rRNA synthesis.

8

Ribosomes

Can be bound (on the rough ER) or free floating within the cytoplasm, and takes part in protein synthesis.

9

Peroxisomes

Found in both plants and animals. and contain "catalase," which converse peroxide (H2O2) into water. Can also detoxify alcohols in the liver.

10

Endomembrane System

Regulates protein traffic and metabolic functions. Includes the golgi apparatus, ER, vacuole, vesicles, lysosomes, nuclear envelope, lysosomes, and the plasma membrane.

11

Nucleus

Has a selectively permeable "nuclear envelope" with pores that separates the stuff inside the nucleus from the cytoplasm.

12

Endoplasmic Reticulum

Rough ER: protein synthesis, and covered in ribosomes.
Smooth ER: steroid hormone synthesis, stores Ca2+ ions, and detoxifies drugs and poison from the body.

13

Golgi Apparatus

The mail man of the endomembrane system. It packages and processes substances, which is then secreted to other parts of the cell for export.

14

Lysosomes

Sacs of hydrolytic enzymes that plays a major role in intercellular digestion. The enzymes also play a role in apoptosis, or cell suicide.

15

Mitochondria

Site of cellular respiration, and present in both plants and animals. Mitochondria have a double membrane and cristae, which contain their own DNA.

16

Vacuoles

Large vesicles used for storage.

Plants have a "central vacuole," protists have a "contractile vacuole" to pump out excess water, and food vacuoles play a major part in phagocytosis.

17

Chloroplast

Only present in plants, and absorb light to synthesize sugar for the plant. Chloroplasts have a double membrane and thylakoids to function in photosynthesis.

18

Cytoskeleton Function

1. Maintain cell shape.
2. Protection.
3. Anchors them to the plasma membrane.
4. Involved in the flow of cytoplasm.

Composed of microfilaments and microtubules.

19

Microtubules

Make up the cilia, flagella, spindle fibers, etc. Often assists in structures that require movement.

20

Microfilaments

Help maintain the shape of the cell using actin filaments.

21

Cell Wall

Made of cellulose. Has primary cell wall, secondary cell wall, and the middle space called the middle lamella.

22

Plasma membrane

Selectively permeable membrane that regulates what enters and exits the cell.

23

Fluid Mosaic Model

Model that states the eukaryotic plasma has a phospholipid bilayer with proteins loosely attached to it. These proteins include integral and peripheral proteins, as well as cholesterol molecules.

24

Function of Protein in the Plasma Membrane

1. Transport
2. Enzymatic activity
3. Cell-cell signaling
4. Cell-cell attachments
5. Signal transduction
6. Attachment to the cytoskeleton and extracellular matrix.

25

Passive Transport

Movement of molecules down a concentration gradient from high to low until an equilibrium is reached, and thus does not require any energy. Examples include diffusion and osmosis.

26

Simple Diffusion

Does not require any protein channels, and just naturally occurs.

27

Facilitated Diffusion

Requires the use of hydrophilic protein channels to transport larger, polar materials such as K+, Cl-, Ca2+.

28

Concurrent Exchange

Flow of adjacent fluids in opposite directions that maximize the rate of simple diffusion. Example: fish gills.

29

Diffusion

The random movement of molecules from high to low concentration.

30

Osmosis

Diffusion through a semi-permeable membrane.

31

Hypotonic Solution

The concentration of solute in the beaker is less than the concentration of the solute in the cell which causes the cell to burst (in animals). In plants, the cell wall prevents the cell from bursting, so it simply becomes turgid.

32

Hypertonic

The concentration of solute in the beaker is greater than the concentration of the solute in the cell, which causes the cell to shrink (plasmolysis).

33

Aquaporins

Water channel proteins, which facilitates the diffusion of water molecules through a cell membrane.

34

Active Transport

Movement of molecules against a gradient, which requires energy. Examples include pumps and carriers.

35

Sodium-Potassium Pump

An example of active transport. Pumps Na+ and K+ across the nerve cell membrane to return back to resting state.

36

Electron Transport Chain

An example of active transport. Consists of proteins that pump protons across the crust membrane

37

Contractile Vacuole

An example of active transport. The freshwater Protista ejects excess water that has already been diffused because the cell lives in a hypotonic environment.

38

Pinocytosis

"Cell drinking." Involves the uptake of large, dissolved particles through vesicles.

39

Phagocytosis

"Cell eating." Uptake of large particles using vacuoles.

40

Receptor Mediated Endocytosis

Enables a cell to take up large amounts of a specific substance. Occurs when extracellular substances (ligand) bind to receptors on the cell membrane and cause the membrane to turn inwards, which then pinches off and becomes a "coated vesicle" in the cell.

41

Bulk Flow

Overall movement of fluid in one direction in an organism.

42

Cell Communication: Cell Contact

Examples include gap junctions in animal cells and plasmodesmata in plant cells. Gap junctions and plasmodesmata allow the passage of material from the cytoplasm of one cell to the cytoplasm of another cell.

43

Cell Communication: Paracrine Signaling

Release of local signals, such as growth factors, from one cell to many more

44

Cell Communication: Long Distance Signaling

A characteristic of the endocrine system where hormones are released in once place and are circulated to far away organs and locations through blood flow.

45

Cell Membrane Receptors

Span the entire length of the membrane, so it touches both the cytoplasm and the extracellular fluid. Hydrophilic (polar) receptor molecules cannot pass through the membrane with diffusion, so they bind to a part of the cell membrane receptor, which changes its shape, and the signal is carried through.

Then, once in the cell, the signal is carried by a cAMP.

46

Ion Channel Receptors

Involves a receptor that opens and shuts a gate that allows an influx of ions, such as Na+, K+, Cl-, Ca2+.

47

G-Protein Coupled Receptors

Span the entire cell membrane. When the signaling molecule binds to the extracellular area of the receptor, it changes the cytoplasmic side.

48

Receptor Tyrosine Kinases

Individual units aggregate and activate the tyrosine region.

49

Three steps of Cell Signaling

Reception: Binding of the ligand to the cell membrane receptors.

Transduction: conversion of the signal to a response.

Response: transduction brings out a response in the cytoplasm or nucleus.

50

Signal Transduction Pathway

- Can cause a cascade affect.
- Evolves from a common ancestor.
- Comes from a signal and a transduction.
- Can be highly specific.