Chapters 3 & 4 - Cell movement Flashcards
Define Diffusion
the random movement of particles from an area of high concentration to an area of low concentration
Define net movement
the general direction of the movement of particles
If there is a high concentration of glucose outside of a cell, where will the glucose go?
inside the cell, to the area of lower concentration
What are the 3 characteristics of diffusion in living organisms?
- get and remove most substances through diffusion
- plants take in carbon dioxide to do photosynthesis
- oxygen diffuses out of the leaf
Name 3 substances that get diffused in organisms
Options:
- glucose
- sodium ions
- nitrate ions
- CO₂
- O₂
Explain the function of water in the human body
Water helps move food through, and helping dissolve food in the digestive system. It also helps remove waste through urine. Blood is 90% water.
Define Osmosis
the diffusion of water molecules through a partially permeable membrane
Why do water molecules go through the partially permeable membrane?
to even out any difference in concentration
Water molecules will go from an area of low concentration to an area of _____________.
high concentration
Define hydrostatic pressure (osmotic pressure)
the pressure exerted by a fluid due to the force of gravity acting upon it
How does the osmotic pressure increase?
if there is a higher difference in concentration, the osmotic pressure will increase
Where does the energy for net movement come from?
the kinetic energy that all particles have
Define turgor pressure
the force within a cell that squishes the cell membrane against the cell wall
Define turgid
turgid within cells makes it firm/rigid (filled cell)
Define flacid
when cells are soft and contracted due to plasmolysis
Define plasmolysis
contraction of the plant cell when it loses water from being in a hypertonic solution
Define hypertonic solution
higher concentration of solute in solution
Define active transport
the movement of particles through a partially permeable membrane from an area of low concentration to an area of high concentration
How do carrier proteins help with active transport?
the carrier proteins contract to change the direction in which an ion can go through (in and out of the cell)
What are humans made of?
- 62% water
- 16% protein
- 16% fat
- 1% carbohydrates
- 5% other (calcium & phosphorus in bones, ions)
- <1% DNA
Which elements are present in all biological molecules and which ones are in biological molecules sometimes?
carbon, oxygen and hydrogen are always in biological molecules. phosphorus and nitrogen are sometimes in biological molecules.
What would happen to an animal cell if the water potential outside the cell was too high? Why can’t this happen to plant cells?
the cell would burst because animal cells don’t have a cell wall. this could not happen to plant cells because they have a cell wall.
Name 3 examples of carbohydrates
- starch
- glycogen
- cellulose
What biological molecule makes up fats and oils?
lipids
Determine the state at room temperature of the following:
- fats
- oils
fats: solids at rtp
oils: liquids at rtp
Select the correct word to fill in the blanks:
Lipids are soluble/insoluble in water
lipids are insoluble in water
Which 3 elements do lipids contain?
carbon, hydrogen, oxygen
What is the structure of lipids?
one glycerol and 3 fatty acids joined with chemical bonds
What is the basic unit of carbohydrates?
glucose
What is the basic unit of lipids?
one glycerol and 3 fatty acids
What is the basic unit of proteins?
amino acids
Do cell membranes contain fats?
yes
What are the 3 characteristics of fats in an organism?
- energy storage
- fat stores more energy per than carbohydrates
- dissolves in ethanol
What is the test for fats?
ethanol emulsion test
Explain the ethanol emulsion test
liquid containing 2 substances that do not fully mix. one forms tiny droplets dispersed through the other
positive result - cloudy liquid
negative result - clear liquid
What are the three characteristics of proteins?
- amino acids linked together
- each have a specific amino acid sequence
- even if one amino acid is altered, chain protein becomes different
What elements do amino acids contain?
carbon, hydrogen, oxygen, nitrogen
How many different amino acids are there?
20+
What are the 3 functions of proteins?
- building blocks of biology
- most of cell structure is made of proteins
- proteins can be structural or active
Name 4 examples of proteins
- keratin (nails and hair)
- enzymes
- hemoglobin
- antibodies
What is the test for proteins?
biuret reagent
positive result - purple
negative result - blue
Explain the biuret reagent test
a blue solution that turns purple when mixed with amino acids or proteins
Is Vitamin C a carbohydrate, a fat or a protein?
neither, it’s a vitamin
What is the test for vitamin c?
DCPIP
What is the positive result for the DCPIP test?
positive result- if the solution goes colorless
What is the test for carbohydrates?
Iodine - starch
positive- blue/black
negative- orange
Benedicts solution - glucose
positive- red/orange (spectrum of color)
negative- blue/green
Name 3 examples of lipids
- oils
- butter
- cell membrane
What is the basic unit for DNA?
nucleotide → bases → A,C,T,G
What are the 5 main characteristics of DNA?
- makes up chromosomes
- sequences of DNA with a function (genes)
- every nucleus in the body contains DNA
- we inhert DNA from our parents
- double stranded
What is a ‘code’ in DNA
a substance the DNA carries which tells the cell which protein to make
What determines the ‘code’ in DNA?
the sequences of the bases (A,C,T,G)
could metabolic reactions occur without DNA?
no
Define nucleotides
molecules that are linked together into long chains to make up a DNA molecule
What do nucleotides contain?
bases
Define base
one of the 4 components of DNA. the sequence of the 4 bases (A,C,T,G) determines the protein that is made in the cell.
Which bases pair together?
A - T
G - C
