Chapter 4 Flashcards

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1
Q

What is the difference between a prokaryotic and eukaryotic cell?

A

A eukaryotic cell has a true nucleus, membrane-bound organelles and is larger and more complex than the prokaryotic cell (prokaryotic cell 1/10 the size). In a prokaryotic cell, DNA has to be kept in the nuceloid region

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2
Q

what things do all cells have in common?

A

a plasma membrane, ribosomes, and DNA as hereditary material

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3
Q

what are some structures of the prokaryotic cell?

A

there may be a fairly rigid cell wall outside plasma membrane. there may be a capsule, a fairly sticky outer coat that surrounds cell wall and helps glue prokaryotes to surfaces. pili also help it attach. finally, it may have a flagella, which is usually only 1 and helps propel prokaryotic cell thr liquid environment

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4
Q

what are some additional names for the plasma membrane?

A

cell membrane/ phospholipid biilayer

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5
Q

what is the function of the cell membrane?

A

it acts as a barrier between the inside and outside of cell “gatekeeper”

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6
Q

why is the cell membrane described as a fluid mosaic model?

A

it acts more like a liquid than a solid. it is like a mosaic because it is made up of many different pieces

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7
Q

what is the cytoplasm?

A

fluid-filled interior of the cell contained by plasma membrane. holds cytoskeleton and all organelles except for nucleus

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8
Q

name and describe the parts of the nucleus

A

nuclear envelope- double membrane separating nucleus from cytoplasm
nuclear pores- tiny, protein-lined holes in nuclear envelope that allow substances like RNA to pass through
nucleolus- central region of nucleus where building blocks of ribosomes are produced
nucleoplasm- jelly-like liquid that fills nucleus

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9
Q

what are the functions of the nucleus?

A

it’s a control center for the eukaryotic cell; contains genetic material (DNA) which directs protein synthesis

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10
Q

what does the DNA in the nucleus look like?

A

DNA is attached to proteins that form long fibers called chromatin. Each chromatin fibers a chromosome (DNA is in chromatin form when cell is not dividing, but in form of chromosomes when it is

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11
Q

what is the golgi apparatus and what is its function?

A

it takes in and modifies, chemically, the substances created by the ER. it finishes, stores and then ships cell products to different destinations through the use of vesicles

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12
Q

what is a flagellum and what is its function

A

long, whiplike structure that sticks out from the cell’s surface. not as many per cell as cilia. its function is to aid the cell in movement

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13
Q

what are cilia and what is their function

A

they are short, hair-like projections that occur in copious amounts. they aid cell in movement.

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14
Q

what are ribosomes, where are they found and what is their function?

A

ribosomes are small, roughly spherical subunits made of protein and RNA. they are where proteins are made and are found in the cytoplasm or on the Roiugh ER.

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15
Q

what are lysosomes and what is their function

A

they are spherical membranous organelles that contain digestive enzymes, so they help break things down. contain acidic environment isolated from the test of cytoplasm. they are types of vesicles, small, membrane-bound sacs that transport substances in cells

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16
Q

what are some examples of lysosome digestive functions?

A

protist engulf food into food vacuoles, in which lysosomes break down food releasing nutrients to the cell. white blood cells ingest bacteria which lysosome enzymes rupture. lysomes fuse with damaged organelles to recycle their contents and allowing organic molecules to be re-available for use

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17
Q

what is the endoplasmic reticulum and what are the two types?

A

it is an extensive network of flattened sacs and tubes. the smooth ER and Rough ER

18
Q

what is the smooth ER and what are its functions?

A

has enzymes embedded in membrane but no ribosomes on surface. it makes lipids. it also breaks down toxins (with help from enzymes in membrane) It also sotres calcium ions

19
Q

what are some examples of Smooth ER functions?

A

ovaries and testes synthesize steroid sex hormones so they have Smooth ER. Liver cells break down toxins so it has Smooth ER. When nerve signal stimulates a muscle cell,. calcium ions come from Smooth ER and into cytoplasm and trigger a contraction of cell

20
Q

what is the rough ER and what are its functions?

A

it has ribosomes studded on surface. it helps transport proteins made by its ribosomes. it also makes more membrane by inserting some protein made by its attached ribosomes into membrane. it also modifies proteins that will be transported to other organelles or secreted by the cell.

21
Q

what are the steps of protein synthesis?

A
  1. ribosomes make polypeptides 2. they are passed into Rough ER where they are folded into specific shape 3. sugar chains may be linked to polypeptide making it a glycoprotin 4. ER packages it into transport vesicle 5. vesicle takes protein to Golgi for further processing 6. transport vesicle takes finished molecule to plasma membrane to be released from cell
22
Q

what is the cytoskelton and name its parts?

A

protein fibers nested all through out cytoplasm, providing structural support and aiding inner-cell movement. Microtubules, micro filaments, intermediate filaments.

23
Q

what are microfilaments?

A

solid rods mainly made of globular protein actin. it is arranged in a twisted double chain and interacts with other protein filaments to make cells contract

24
Q

what are intermediate filaments

A

they are made of fibrous proteins in rope like structure. they reinforce cell shape and anchor certain organelles

25
Q

what are microtubules

A

straight hollow tubes of globular protein tubulin. provide anchorage for organelles. act as a highway system for organelle movement within cytoplasm and for transportation of info from nucleus to other parts of cell

26
Q

what is function of mitochondria?

A

they carry out cellular respiration, converting chemical energy of foods into ATP

27
Q

what are parts of mitochondria?

A

outer membrane, inner membrane. the inner membrane contains fluid called mitochondrial matrix and folds called cristae. cristae are embedded with enzymes that make ATP called ATP synthase.

28
Q

what do junctions do and what are the junctions

A

they connect adjacent cells in many animal tissues. tight junctions- bind cells very tightly forming leakproof sheet anchoring junction- rivet cells together with cytoskelal fibers, forming strong sheets. gap junctions- channels allowing small molecules to flow between neighboring cells.

29
Q

what is the difference in structure between plant and animal cells?

A

only the sperm cells of a few plants have flagella. animal cells do not have cell walls, chloroplasts, or central vacuoles, while plant cells do

30
Q

what is the cell whall and what is its function

A

helps support and maintain shape of cell, keeping plants upright on land. it also protects the cell from damage and is 10-100x thicker than plasma membrane. it consists of cellulose embedded in matrix of polysaccharides and proteins lignin- rigid molecules that strengthen cell wall of many plants.

31
Q

what is a chloroplast and what is its function?

A

use light energy to make carbohydrates from Co2 and H2o; photosynthesis. contains some DNa and ribosomes and make some of its own protein.

32
Q

name and describe the parts of the chloroplast

A

consists of inner & outer membrane. stroma- thick fluid inside space enclosed by inner membrane thylakoid- hollow membrane disks grans- stacks of thylakoids. where chlorophyll traps solar energy.

33
Q

what is the central vacuole and what is its function

A

membrane-bound space that takes up much of plant cell volume. soteres water, chemicals, nutrients and wastes. when full is rigid and allows cell to stand upright. also may contain pigments that attract pollinating insects. some contain poisons to protect against animals.

34
Q

how can plant cells function as tissue

A

cells must have cell junctions, so therefore there are plasmodesmata channels between adjacent plant cells that form a circulatory and communication system connecting the cells in plant tissues. through plasmodesmata, cells of plant tissues share water, nourishment and chemical messages

35
Q

who are the important people to know in cell history?

A
robert hooke- discovered cell wall
anton van leeuwenhoek- discovered living cell
schleiden- all plants are made of cells
schwann- all animals are made of cells
virchow-all cells come from cells
36
Q

what is the cell theory

A
  1. all living organisms are composed of 1+ cells 2. cells are basic unit of structure & function 3. cells come only from reproduction of existing cells
37
Q

explain how cell structure is related to function

A

nerve sell is long to send and receive nerve impulses. skin cells are flat and plate-like

38
Q

explain surface area to volume ratio

A

cells need enough surface area to obtain adequate nutrients and oxygen from the environment and dispose of waste

39
Q

what is the difference between magnification and resolution?

A

magnification- increase in apparent size of an object

resolutin- measure of clarity of image

40
Q

what is a light microscope?

A

passes visible light thru specimen. glass lenses bend light to make image bigger. used for living cells. ocular lens magnifies 10x

41
Q

what are electron microscopes

A

use particle beam of electrons to illuminate specimen and highly magnify. cannot view living cells

42
Q

what is the difference between scanning electron microscope and transmission electron microscopes?

A

scanning- coated in thin metal layer, 3D image of cell surface
transmission- stained with gold, shows internal structure