Chapter 6 Flashcards Preview

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Flashcards in Chapter 6 Deck (50):
1

Biologists use ___ and ___ to study ___

microscopes, biochemistry, cells

2

Cell walls were first seen by

Robert Hooke

3

Who first saw living cells?

Antoni van Leeuwehoek

4

light microscope (LM)

visible light passed through specimen and glass lenses; lenses refract light to magnify image

5

3 parameters for microscope

magnification, resolution, contrast

6

magnification

ratio of object's image size to real size

7

resolution

clarity of image; min distance 2 points can be separated and still be distinguished as separate points

8

contrast

difference in brightness between light/dark areas

9

organelles

membrane-enclosed structures within eukaryotic cells

10

electron microscope (EM)

focuses beam of electrons through specimen/onto surface
resolution is inversely related to wavelength of light/electrons

11

scanning electron microscope (SEM)

detailed study of topography of specimen
electron beam scans surface of sample, which excites electrons on the surface and they're detected by a device that translates the pattern of electrons into an electronic signal

12

types of LM

brightfield (stained/unstained), phase contrast, differential-interference-contrast (nomarski), fluorescence, confocal, deconvolution, super-resolution

13

types of EM

SEM and TEM

14

transmission electron microscope (TEM)

study internal structure of cells
aims electron beam through very thin section of specimen
use electromagnets as lenses to bend paths of electrons

15

cytology

study of cell structure

16

biochemistry

study of chemical processes (metabolism) of cells

17

cell fractionation

technique for taking cells apart and separating major organelles and sub cellular structures from one another
uses centrifuge which spins around test tubs w/ mixtures of disrupted cells at series of increasing speeds
resulting force causes subset to settle to the bottom of tube
enables bulk of a specific cell component

18

___ cells have internal membranes and ___ their functions

eukaryotic, compartmentalize

19

cytosol

semifluid, jellylike substance, in all cells, subcell components suspended in

20

chromosomes

carry genes in DNA form

21

ribosomes

make proteins according to gene instructions

22

eukaryotic cell

DNA in nucleus, bound by double membrane

23

prokaryotic cell

DNA concentrated in region not membrane enclosed (nucleoid)

24

cytoplasm

region between nucleus and plasma membrane
interior of either type of cell

25

which is larger: eukaryotic/prokaryotic?

eukaryotic

26

plasma membrane

selective barrier for passage of O2, nutrients, wastes; encloses cell

27

larger organisms don't have larger cells

just have more cells

28

microvilli

long, thin projections that increase SA w/o increase in volume

29

flagellum

motility structure present in some animal cells
comprised of cluster of microtubules within an extension of plasma membrane

30

centrosome

region where cell's microtubules are initiated
contains pair of centrioles

31

cytoskeleton

reinforces cell's shape; functions in cell movement; component are made of protein; includes microfilaments, intermediate filaments, microtubules

32

peroxisome

organelle w/ various specialized metabolic functions; produces hydrogen peroxide as by product, then converts to water

33

mitochondrion

organelle where cell respiration occurs and most ATP is generated

34

endoplasmic reticulum (RER/SER)

network of membranous sacs and tubs; active in membrane synthesis and synthetic/metabolic processes
has rough and smooth regions

35

nuclear envelope

double membrane enclosing nucleus, perforated by pores, continuous w/ ER
nucleus

36

nucleolus

nonmembrane structure involved in production of ribosomes; nucleus has 1+ nucleoli
nucleus

37

chromatin

material consisting of DNA and proteins; visible in dividing cell as individual condensed chromosomes
nucleus

38

ribosomes

complexes that make proteins; free in cytosol/bound to RER/nuclear envelope

39

Golgi apparatus

organelle active in synthesis, modification, sorting, secretion of cell produts

40

lysosome

digestive organelle where macromolecules are hydrolyzed

41

central vacuole

prominent organelle in older plant cells; storage, breakdown of waste products, hydrolysis of macromolecules

42

choloroplast

photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules

43

plasmodesmata

cytoplasmic channels through cell walls that connect the cytoplasms of adjacent cells

44

cell wall

outer layer that maintains cell's shape and protects cell fr mechanical damage; made of cellulose, other polysaccharides, protein

45

____ cell's genetic instructions are housed in the ___ and carried out by the ___

eukaryotic, nucleus, ribosomes

46

nucleus

contains most of genes in eukaryotic cells; most conspicuous organelle

47

nuclear envelope

encloses nucleus; double membrane w/ phosopholipid bilayer

48

nuclear lamina

netlike array of protein filaments that maintain shape of nucleus by mechanically supporting the nuclear envelope; lines nuclear side of envelope

49

chromosomes

carry genetic info; contains 1 long DNA molecule associated w/ many proteins

50

chromatin

DNA and proteins making up chromosomes