YR11 - Topic Test 1 - Cells, Moving Through Plasma Membrane Flashcards

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1
Q

cells

A
  • they are the basic unit of all living things
  • they come from pre-existing cells
  • smallest living organisational unit
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2
Q

prokaryotic cells vs eukaryotic cells

A

prokaryotic cells have no nucleus circular DNA and no membrance bound organelles (bacteria) whereas eukaryotic cells have a nucleus, linear DNA and membrane bound organelles (animals and humans)

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3
Q

nucleus

A

contains DNA and controls cells activity

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4
Q

rough e.r.

A

controls what goes in and out of the cell, produces proteins

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5
Q

smooth e.r.

A

makes cellular products like hormones and lipids.

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6
Q

mitochondria

A

where aerobic respiration takes place, converts ATP into glucose, this process is known as respiration

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7
Q

ribosomes

A

where protein synthesis occurs

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8
Q

golgi apparatus

A

modifying, sorting and packaging of proteins for secretion. It is also involved in the transport of lipids around the cell, and the creation of lysosomes

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9
Q

chloroplast

A

found in plant cells. Contain chlorophyll that absorbs light for photosynthesis.

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10
Q

large vacuole

A

found in plant cells. Contain a fluid called cell sap Stores fluids, nutrients and waste.

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11
Q

cell wall

A

found outside the cell membrane in only plant cells and provides support for the cell

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12
Q

similarities plant vs animal cells

A

vacuoles, cell membrane, nucleus, mitochondria, cytoplasm, endoplasmic reticulum, ribosomes, golgi body

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13
Q

differences plant vs animal cells

A

vacuoles are noticeably bigger in a plant cell, plant cells have a cell wall and chloroplast

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14
Q

how does the shape of a plant cell differ from that of an animal cell?

A

a plant cell has a cell wall which helps it maintain a rigid structure whereas an animal cell has no cell wall

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15
Q

light microscope

A

uses light and a system of lenses to magnify the image

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16
Q

electron micropscope

A

an object is viewed using an electron beam instead of light. this allows us to see structures in far more detail

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17
Q

difference between light and electron microscope

A

electron microscopes allow us to see structures in far more detail than is possible using a light microscope

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18
Q

phospholipids

A

a fat-like substance, usually based on glycerol. Phospholipids are essential components of cell membranes. They are involved in the uptake of fats and fatty acids from the products of digestion

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19
Q

lipid bilayer

A

(or phospholipid bilayer) is a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells.

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20
Q

transport proteins (carrier proteins)

A

a transport protein that changes shape when molecules bind to it, so that the molecules can pass through the plasma membrane. they take part in facilitated diffusion and active transport

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21
Q

channel proteins

A

a transport protein that molecules do NOT usually bind to. they allow specific molecules to pass through the plasma membrane, and are used in facilitated diffusion.

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22
Q

cholesterol

A

a steroid lipid found in most body tissues. it is an important component of cell membranes in animals and is used to form other steroid compounds.

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23
Q

plasma membrane structure

A

cholesterol, channel and carrier proteins, carbohydrate chain, glycoprotein, cytoskeleton filaments etc.

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24
Q

simple diffusion

A

Simple diffusion is the process by which solutes are moved along a concentration gradient in a solution or across a semipermeable membrane from a high concentration to a low concentration

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25
Q

facilitated diffusion

A

the process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins. Being passive, facilitated transport does not directly require chemical energy

26
Q

osmosis

A

the movement of water or other solvent through a plasma membrane from a region of low solute concentration to a region of high solute concentration, tending to equalise the concentrations of the solutes. Osmosis is passive transport, meaning it does not require energy to be applied.

27
Q

active transport

A

the movement of molecules across a membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement.

28
Q

hypertonic

A

refers to a solution with higher osmotic pressure than another solution. In other words, a hypertonic solution is one in which there is a greater concentration or number of solute particles outside a membrane than there are inside it

29
Q

hypotonic

A

any solution that has a lower osmotic pressure than another solution. In the biological fields, this generally refers to a solution that has less solute and more water than another solution

30
Q

isotonic

A

refers to two solutions having the same osmotic pressure across a semipermeable membrane. This state allows for the free movement of water across the membrane without changing the concentration of solutes on either side.

31
Q

what are 3 ways to increase the cell surface area to volume ratio

A
  • cell compartmentalisation
  • a flattened shape
  • plasma membrane extensions

Increasing the size of a cell will increase
membrane surface area but the volume of the cell
will also increase.

32
Q

why are cells small

A

so that it helps the cells to maximise their efficiency in exchanging matter with their environment

33
Q

what structures are visible to a light microscope

A

nucleus, cytoplasm, cell membrane, chloroplasts and cell wall. Mitochondria are also visible under light microscope but detailed study is not possible.

34
Q

surface area: volume ratio

A

the cell is small (ratio) so that the surface area is bigger so the cell can receive more nutrients from the bigger SA

35
Q

which shape has the highest SA:V ratio

A

any shape that is longer and thinner has a higher SA:V ratio than say a cube shape

36
Q

Cells that have a high rate of metabolism would also need a

A

large surface area to volume ratio because Cells with a high rate of metabolism would need to exchange materials with their external environment rapidly and would therefore need a large surface area to volume ratio.

37
Q

three structures are visible with a light microscope?

A

nucleus, vacuole, chloroplast

38
Q

as a cell grows larger,

  • the surface area
  • what is a consequence to the cell
A

decreases

become less efficient in expelling wastes

39
Q

what is a disadvantage of using an electron microscope

A

can’t view living specimen

40
Q

what is an advantage of using a electron microscope

A

greater resolution and magnification

41
Q

2 differences between eukaryotic and prokaryotic cells

A

prokaryotic cells are smaller (1-2ym) than eukaryotes

eukaryotes have a membrane-bound nucleus, prokaryotes don’t

42
Q

2 functions of both common cell types

A
  • both store water and nutrients (sustain life)

- both transport materials through the plasma membrane

43
Q

ribosomes are found in both-

A

prokaryotic and eukaryotic cells

44
Q

explain what is meant by the terms ‘fluid’ and ‘mosaic’ when describing the plasma membrane

A

fluid in fluid mosaic model refers to the fatty chains of the phospholipids that are like a thick, oily fluid. The term mosaic refers to the external surface that has various embedded proteins in the formation of a mosaic

45
Q

explain how compartmentilisation aids the efficient functioning of eukaryotic cells

A
  • increases SA:V
  • optimal conditions established
  • specialised conditions
  • parts of cytoplasm seperate from cytosol
46
Q

similarity and difference between simple and facilitated diffusion

A
  • both passive processes (no ATP)
  • simple - straight through phospholipid bilayer
  • facilitated - through protein channels
47
Q

what characteristic of water enables it to move through the lipid bilayer that forms the plasma membrane of a cell

A

water is polar, hence it is able to move through the lipid bilayer as it is also polar
- small, fit through gap

48
Q

describe what might happen to a marine plant when placed in distilled water

A

the plant will absorb the water increasing and decreases the salt concentration
- plant cells become full or water - turgid

49
Q

a biomacromolecule is

A

a large complex molecule-polymer made up of smaller units called monomers

50
Q

lipids are NOT biomacromolecules because

A

they do not consist of repeating monomers

51
Q

polar molecules

A

have a charge differential. This means they have a positively charged area and a negatively charged area

52
Q

ions

A

are positively or negatively charged atoms

53
Q

how a solute dissolves in h2o which is polar

A

each polar solute is either a positive or negative which attract one of the other. H2O has a positive and negative ion which each attracts to one of the other. the positive/negative ion pulls the opposite one away. This causes the solute to dissolve

54
Q

what would happen if the solute was uncharged and mixed with water, why?

A

if the solute was uncharged and mixed with water, nothing would happen because there was no attraction to pull apart/dissolve

55
Q

plasma membrane

A

acts as a boundary between the inside and outside of cells so that it can control what goes into the cell and what comes out of the cell

56
Q

it’s an advantage for the membrane to be non-polar because..

A
  • non-polar molecules are insoluble in water

- it will stay intact thus acting as a cell boundary

57
Q

the membrane forms a bilayer (rather than a single layer) because..

A
  • lipids are hydrophobic so they stay away from water
  • it forms the two laters so that it is protected from water on the inside and outside of the cell
  • the hydrophillic phosphates on the edges of the lipids act as a barrier between the water and lipids
58
Q

diffusion

A

when particles spread out from an area of high concentration to low concentration. high - low is the concentration gradient. the process is passive as it doesn’t use energy.

59
Q

SA:V high surface area:volume ratio characteristics

A
  • would survive best in hot climates
  • most efficient at removing wastes
  • most efficient at exchange across cell membrane
60
Q

SA:V low surface area:volume ratio characteristics

A
  • would survive best in cold climates
  • least efficient at exchange across membrane
  • least efficient at removing waste