Chapter 4 / 5 Flashcards Preview

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Flashcards in Chapter 4 / 5 Deck (43):
1

Cells

-smallest living units

-display ALL properties of life

2

Cells were discovered in 1600’s by ______ (in cork)

Robert Hooke

3

Anton van Leeuwenhoek observed living single-______

-celled organisms

4

3 Basic Parts Of A Cell

1) cytoplasm

2) nucleus

3) plasma membrane

5

Plasma Membrane

-controls what goes in/out of cell

6

Nucleus

-controls cells functions

-stores DNA

7

Cytoplasm

-contains organelles that carry out special functions, everything w/in membrane EXCLUDING nucleus

-70% water

7

Cells surface area to _____ sets the upper limit to its size

volume ratio

8

Greater the # of ACTIVE cytoplasm the...

-more materials used / wastes produced

9

Plasma membrane is made up of

lipids & proteins

10

Greater the surface area the....

FASTER substances are exchanged

11

As a cell’s diameter increases its volume...

it grows faster than SURFACE area

-perfect sphere has maximum volume

12

Cells w/ altered shapes may get around _____

constraint

ex. long thin nerve cells

13

Cell Theory

1) all living things are made of one or MORE cells

2) all cells came from PREEXISTING cells

3) basic living units w/i ORGANISMS

14

Prokaryotes lack a

nucleus

15

Eukaryotes are LARGER then

prokaryotes

16

Eukaryotes contain

MEMBRANE-bound nucleus + other organelles

17

Colonial- consists of

1) cluster of cells

2) survive independently

18

Multicellular - cells usually perform

specialized tasks
ex. Plants + Animals

19

Fluid Mosaic Model**

1) phospholipids make up bulk of membrane

2) DESCRIBES structure of cell membrane***

3) proteins are embedded in the lipid BILAYER

20

Each phospholipid has a _______ _____ & ______

HYDROPHOBIC head & tail

21

When surrounded by H2O, phospholipids align as

-lipid bilayer

(part of molecule likes water, part DOES NOT)

22

Membrane fluidity varies among...

cells specialized for certain environments

ex. penguins on ice, lipids RESIST freezing

23

Selectively Permeable:

things pass through membrane

24

Diffuse through membranes?

INORGANIC molecules, very small

25

Substances that pass through membranes?

FAT-soluble organic substances

26

Compounds that pass through certain membrane PROTEINS

WATER-soluble organic

27

Endocytosis

-move INTO cell of large molecule

28

Exocytosis

-removal waste of proteins, OUTSIDE cell

29

Nuclear Envelope

-DOUBLE-layered membrane

-surrounds nucleus

30

Genetic info passes from DNA ---> ___ --->______

RNA ----> proteins

31

Pores in membrane allow...

RNA to escape

32

______ carry out work of cell

proteins

33

Chromosomes

form when DNA + protein change at start of cell division

34

______ makes Ribosomal RNA

nucleolus

35

Ribosomes

site of PROTEIN synthesis

36

Cytoskeleton

- 3D structure fibers

-keeps cell’s shape

-moves materials in cell

37

3 Types of Fiber

1) microtubules

2) microfilaments

3) intermediate filaments

38

Microfil A ments

-made of protein actin

39

Actin

MOLECULES in unrelated organisms are similar, suggests ancient origin

40

Microtubules

-hollow tubes of protein TUBLIN

41

Spindle Apparatus

-moves CHROMOSOMES around during mitosis

42

Intermediate Filaments

-keratin + other proteins

-nails, hair, feathers, skin

-reinforcement