Bio Final Exam: big pack Flashcards
What do all living organisms have in common? (MRS C GREN)
-Movement
-Respiration
-Sensitivity
-Control
-Growth
-Reproduction
-Excretion
-Nutrition
What are the subcellular structures found in animal and plant cells? (5)
-Nucleus
-Cytoplasm
-Cell membrame
-Mitochondria
-Ribosomes
Nucleus:
-Contains the genetic material, which codes for a particular protein
-Enclosed in a nuclear membrame
Cytoplasm:
-Liquid substance in which chemical reactions occur
-Contains enzymes (biological catalysts, i.e proteins that speed up the rate of reaction
-Organelles are found in it
Cell membrame:
-Contain receptor molecules to identify and selectively control what enters and leaves the cell
Mitochondria:
-Where aerobic respiration reactions occurs, providing energy for the cell
Ribosomes:
-Where protein synthesis occurs
-Found on a structure called the rough endoplasmic reticulum
What do Plants contain?
E.g. cereals (maize) or herbaceous legume (peas)
-Multicellular organisms
-Contain chloroplats
-Cellulose cell walls which provide strength to the cell
-Contain a permament vacuole, stores cell sap + improves cell’s rigidity
-Store carbohydrates as starch or surcrose
What do Animals contain?
E.g. mammals (humans) and insects (flies)
-Multicellular
-Can’t photosynthesise
-Don’t have cell walls
-Have nervous systems in order to coordinate movement
-Store carbohydrates as glycogen
What do Fungi contain?
-E.g. Mucor has a typical hyphal structure, yeast is single celled
-body is usually organised into a mycelium of thread-like structures called hyphae
-cell walls made of chitin
-feed by saprotrophic nutrition
-store carbohydrates as glycogen
What are Protoctists?
-Single-celled organisms
-Some features like animal cells, such as Amoeba, that live in pond water
-Some features like plant cells + have chloroplasts, such as Chlorella
What are Eurokaryotes?
-> organisms that have a nucleus and organelles that are found within a plasma membrane
What are Prokaryotes?
-> don’t have a nucleus or membrane-bound organelles
What does Bacteria contain?
E.g Lactobacillus bulgaris (used to make yoghurt), Pneumoccocus (causes pneumonia)
-single-celled + very small
-have a cell wall, cell membrane, cytoplasm + plasmids
-lack a nucleus but have circular chromosomes of DNA
-some can carry out photosynthesis but they mainly eat off other organisms, either dead or alive
What are Pathogens?
-Disease-causing organisms and can be fungi, bacteria, protoctists or viruses
What does a Virus contain?
E.g. Tobbaco mosaic virus (prevents chloroplast formation), influenza virus (causes ‘flu’), HIV (causes AIDS)
-smaller than bacteria
-some are parasite: it depends on another organism to grow and reproduce
-infect all types of living organisms
-they have a protein coat around some genetic material (DNA or RNA)
Why is Bacteria a pathogen?
E.g. Salmonella (food poisoning)
-can reproduce many times through binary fission
-produce toxins that can damage cells
Why are Protoctists a pathogen?
E.g. plasmodium -> malaria
-parasitic- use animals as their hosts to live in
Why is Fungi a pathogen?
E.g. Athlete’s foot
-produce spores that can spread in the wind or between people
-can treat with fungicides
Organelles:
specialised subcellular structures found within living cells
Cells:
basic structural unit of a living organism
Tissues:
group of cells with similar structures, working together to perform the same function
Organs:
group of tissues, working together to perform specific functions
Organ Systems:
group of organs with similar functions, working together to perform body functions
What are only found in plant cells?
-Chloroplasts
-Permament vacuole
-Cell wall
Chloroplasts:
-Where photosynthesis takes place, providing food for the plant
-Contains chlorophyll pigment (which makes it green) which harvests the light need for photosynthesis
Permament vacuole:
-Contains cell sap
-Found within the cytoplasm
-Improves cell’s rigidity
Cell wall:
-Made from cellulose
-Provides strength to the cell
What are Carbohydrates?
-Made of carbon, oxygen and hydrogen
-They are polymers that break down into simple sugars
What are Proteins?
-Made of carbon, oxygen, hydrogen, sulfur, nitrogen and phosphorous
-They are polymers that are broken down into its monomers: amino acids
What are Lipids (fats and oils)?
-Made of carbon, oxygen and hydrogen
-They are large polymers that are broken down into 3 fatty acids molecules + a glycerol molecule
What is the test of glucose?
Benedict’s solution:
If glucose is present: brick red
If glucose is not present: remain brown
What is the test for starch?
Iodine solution:
If starch is present: turn blue-black
If strach is not present: remain brown
What is the test for protein?
Biuret solution:
If protein is present: turn purple
If protein is not present: remain blue
What is the test for lipids?
Ethanol:
If lipids are present: milky white emulsion will form
If lipids are not present: remain colourless
What are Enzymes?
-Biological catalyst
-They are protein molecules and the shape of the enzyme is vital to its function because each enzyme has its own active site where the subsrtate binds
How does the Effect of temperature affect enzymes?
-they optinum is around 37º
-increase in tem. = increase rate of rxn, if it goes above the 37º it rapidly decreases and the rxn stops (bonds are broken if too hot9
-this changes the shape of the active site = substrate can no longer fit in), the enzyme is denatured
How does the Effect of pH affect enzymes?
-optinum pH = 7, but some are produced in acidic conditions (eg: stomach, has a lower pH)
-if the pH is too high or low, the forces hold the amino acid chains that make up the protein will be affected
-same as the active site in the effect of temp.
What is Diffusion?
-> the spreading out of the particles in a net movement from an area of higher concentration to an area of lower concentration
-passive process = no energy is required
-molecules have to be small in order to move across (oxygen, glucose, amino acids, water…), large molecules (starch, protein…) can’t
How does the Concentration gradient affect the rate of movement?
-greater difference in concentration = faster rate of diffusion
-this is because more particles are randomly moving down the gradient than are moving against it
How does the Temperature affect the rate of movement?
-the greater the temperature, the greater the movement of particles, resulting in more collisions and therefore a faster rate of diffusion
How does the Surface area: volume ratio affect the rate of movement?
-the greater the s.a, the more space for particles to move throughm resulting in a faster rate of diffusion
How does Distance affect the rate of movement?
the further the particles have to travel the longer it will take
What is Osmosis?
-> the movement of water from a less concentrated solution to a more concentrated one through a partially permeable membrame
-a dilute solution of sugar has a high
concentration of water (high water potential) and vv
-water moves from a dilute solution to a concentrated solution because it moves from ana area with high water potential to low water potential- down a concentration gradient
-it is passive
What is an Isotonic solution?
If the concentration of sugar in a external solution is the same as the internal, there will be no movement and the solution is said to be isotonic to the cell
What is a Hypertonic solution?
If the concentration of sugar in an external solution is higher than the internal, water moves out, and the solution is said to be hypertonic to the cell