Unit 2 Biology Flashcards
What is diffusion?
Diffusion is when particles move from an area of high concentration to an area of low concentration as a result of their random movement
Where does the energy of diffusion come from?
Kinetic energy
What is the concentration gradient?
Area of high concentration to an area of low concentration
What does passive process mean?
It does not require energy
What are three factors that affect diffusion?
Temperature
Surface area to volume ratio
Concentration gradient
List 4 ways to get a faster rate of diffusion:
Higher temperature
Larger surface area
Smaller size of particles
Higher gradient
In which medium does diffusion occur the fastest?
Gas
What is osmosis?
Osmosis is the diffusion of water molecules from a region of high concentration to a region of low concentration through a partially permeable membrane
What is a partially permeable membrane?
A partially permeable membrane has holes to allow water molecules to pass through but are too small to let larger molecules pass through
How do water particles in osmosis diffuse?
From high concentration to low concentration
What does a dilute solution mean?
Has a high concentration of molecules
What does concentrated solution mean?
Has a low concentration of molecules
What are plant and animal cells surrounded by?
Partially permeable plasma
What does a cell wall provide for a plant cell
Support
Protection
Why is water important for cells?
For chemical reactions
Support
What is active transport?
Active transport is the movement of particles from an area of low concentration to an area of high concentration using energy in the form of ATP
What happens during active transport?
Protein carriers in the cell membrane pick up particles and move them against the concentration gradient
What minerals do plants need to absorb?
Phosphorus
Nitrogen
Potassium
How is active transport used in plants
Is the soil as a low concentration of minerals then the roots can absorb it against the concentration gradient
What are organic molecules
Organic molecules are biological molecules
Which elements does carbohydrates have
C
H
O
What elements do lipids have?
C
H
O
What elements do proteins have?
C H O N S P
What elements do nucleus acid have?
C H O N P
What are monomers?
Monomers are subunits that make up a large organic molecule
What is a polymer?
Polymers is a large molecule made up of a long chain of repeating monomers
What is condensation
Condensation is the process of turning monomers into polymers by removing water
What is hydrolysis?
Hydrolysis is the use of water to break down polymers into monomer
What percentage of our body is water?
70%
Why is water important to living organisms?
Chemical reactions
Transport glucose around the body
Dissolves enzymes
Kidneys will remove waste products
carbohydrates
Monomers?
Glucose
Carbohydrates
Polymers
Disaccharide-sucrose
Polysaccharide - starch
Carbohydrates
Function
Primary fuel
Form cell walls
Storage of available energy
Proteins
Monomers
Amino acid
Proteins
Polymer
Polypeptide
Proteins
Functions
Digest food Transport oxygen Provides immunity Form structures Energy stored for developing embryo
Lipids
Monomers
Glycérol and fatty acids
Lipids
Polymer
Triglyceride
Lipids
Function
Fat stores long term energy
Cushion vital organs from damage
Nucleic acid
Monomers
Nucleotide
Nucleic acid
Polymer
Double stranded helix
Nucleic acid
Functions
Carries genetic info
Determines proteins made in cells and what they develop into
Why can’t lipids be polymers
They do not form large molecules bc they are not made of monomers
What is the food test for starch?
Add 1ml of iodine solution
Mix well
Colour change
Brown to blue black
What is the food test for Protein?
Add 1ml of biuret solution into an Aqueous solution of the food
Mix well
Colour change
Pale blue to purple
What is the food test for reducing sugar?
Add 1ml of Bénédicte solution
Place in water bath for 2min
Colour change
Blue to brick red
What is the test for lipids?
Add 1ml of ethanol
Mix well
Colour change
It turns milky white
What is flaccid
Floppy
What is turgid?
Firm
What is phagocytosis?
Phagocytosis is when particles are engulfed by the cel surface membrane flowing around them
What is plasmolysed?
Plasmolysed is when the cell membrane peels away from the cell wall.
What is cellular metabolism?
The total number of chemical reactions that occur constantly in each living cell
What are biochemical pathways?
Chemical reactions in cells occur in a series of controlled steps and each step in the pathway is controlled by an enzyme
What is an enzyme?
A protein catalyst which speeds up the rate of the reaction without undergoing any change itself
What do enzymes bind with?
They bond specifically to a substrate molecule and convert it to a product molecule. They are not used up in a reaction and so can be recycled.
What do enzymes do?
Enzymes reduce the amount of energy required to begin the reactions
What is the structure of an enzyme?
Enzymes are made of proteins that have been folded so that they have a specific active site which binds to its substrate.
How does enzyme action happen?
- Enzyme and substrate are available
- Substrate binds with enzyme
- Substrate is converted to product
- Products are released
How is the enzyme affected by temperature?
Enzymes work best at 37 degrees
However at high temperatures the enzymes protein structure is permanently changed so that the substrate can no longer bind to the active site.It becomes denatured
What is the optimal temperature?
The temperature at which the enzyme works best at
How is the enzyme affected by the pH?
Each enzyme works best at a particular pH
Enzymes can dénature by extreme pH changes.
What pH does trypsin work in?
8
What pH does pepsine work in?
2
What pH does catalase work in?
7
What does heat do to enzymes?
More collisions between enzymes and substrate
What is turgor pressure?
Turgor pressure is water pressure acting against an inelastic cell wall
What is the test for Vitamin C?
Add DCPIP until the colour changes permanently
from Blue to colourless
What happens to a plant cell when placed in a solution of lower water potential?
It will become flaccid
What happens when a RBC is added to a solution of lower water potential?
It will become crenated
What will happen when RBC is added to a solution of high water potential?
It will swell up and burst
Define Tissue
Group of cells with similar structure to carry out a specific function
Define Organ
Group of tissues working together to carry out a specific function
Define Organ System
Group of organs with related function to carry out a specific function
