Unit 2 - Multi-cellular organisms Flashcards
What are cells?
The living units from which all organisms are made
How many organelles does an animal cell have and what are the organelles?
5 - nucleus, cytoplasm, cell membrane, ribosomes, mitochondria, cytoplasm.
How many organelles does a plant cell have and what are the organelles?
8 - nucleus, cell membrane, ribosomes, mitochondria, cytoplasm, cell wall, chloroplast, sap vacuole.
How many organelles does a bacteria cell have and what are the organelles?
6 - cell membrane, ribosomes, cytoplasm, cell wall, plasmid, DNA (also the flagellum and capsule which is not really classed as structures in the cell)
How many organelles does a fungal cell have and what are the organelles?
7 - nucleus, cytoplasm, cell membrane, ribosomes, mitochondria, vacuole, cell wall
What are single celled organisms?
bacterial
What are multi-cellular organisms?
human
What is diffusion?
Diffusion is the movement of liquid or gas molecules down a concentration gradient from a region of higher concentration to a region of lower concentration until the concentrations are both equal.
What is the structure, arrangement and purpose of the cell membrane?
The cell membranes are extremely thin and are made of phospholipids and proteins. The lipids form two layers called a bi-layer of molecules which are mobile. The arrangement of proteins are found scattered as a mosaic in and around the lipid layers and they can move around the membrane, for this reason they membrane is described as fluid mosaic.The cell membrane controls/selects what enters and leaves the cell as it is selectively permeable.
What is the test for starch?
Iodine solution
What is the test for glucose?
Benedict’s reagent
What is osmosis?
Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration across a selectively permeable membrane
What happens when plant cells gain water by osmosis?
This fills the large vacuole which forces the cell membrane out against the cell wall and the cell has now became turgid.
What happens when plant cells lose water by osmosis?
The large vacuole empties and pulls the cell membrane away from the cell. This is called plasmolysis and the cell is now said to be plasmolysed.
What happens when animal cells gain water by osmosis?
As there is no cell wall the cell membrane eventually ruptures and the cell bursts.
What happens when animal cells lose water by osmosis?
The cell shrinks.
What is active transport?
Transport where energy is required by proteins to move molecules or ions across a selectively permeable membrane from a region of lower concentration to a region of higher concentration against the concentration gradient.
What are the 4 DNA bases?
Adenine, Cytosine, Guanine, Thymine
What do DNA molecules carry?
The different codes for different amino acids and therefor, codes for a protein.
What is a gene?
a section of DNA which codes for a protein. Each gene carries the genetic code for making one protein. Genes carry the genetic instructions to make all the proteins required to build an organism.
What are proteins?
long chains of amino acids
What determines the protein which is produced?
The sequence of amino acids, which is determined by the sequence of bases.
What doe mRNA do?
mRNA carries the code for building a specific protein from the nucleus to the ribosome in the cytoplasm where the protein is assembled form amino acids, therefor acting as a messenger.
What is mRNA bases?
Adenine, Guanine, Cytosine and Uracil.
What are proteins made of?
Hydrogen, Oxygen Carbon and Nitrogen.
What are functions of proteins?
- Structural (e.g. keratin, callagin)
- Hormones (e.g. insulin, testosterone, oestrogen)
- Antibodies (e.g. produced by white blood cells)
- Receptor (e.g. usually found on the outside of cells cell membrane)
- Enzymes (e.g. amylase, lipase, pepsin)
What are enzymes?
Proteins made by all living cells
What are enzymes function as a biological catalyst?
To speed up a chemical reaction and are unchanged by the reaction and can be used again.
What are examples of enzymes?
- Catalase breaking down hydrogen peroxide into water and oxygen
- Pepsin breaking down protein into amino acids
- Amylase breaking down starch into Maltose
What can an enzyme only work on?
It’s specific substrate
What is unique about the shape of an active site of an enzyme?
It is complementary to it’s specific substrate
What is the 5 mark answer for give an account of the properties of enzymes?
- They are specific
- Active site
- Synthesis/Degradation reaction
- Unchanged and can be used again
- Optimum pH/ temp and can be denatured by too high temps and active site shape will no longer attach to substrate as changed shape.
What are the five steps to genetic engineering?
1) Identify section of DNA that contains the required gene from the source chromosome.
2) Extract required gene using enzymes.
3) Extract plasmid from bacteria cell.
4) Insert required gene into bacterial plasmid using enzymes.
5) Insert plasmid into host bacterial cell to produce a genetically modified organism.
What are uses of genetic engineering?
- Insulin for the control of diabetes
- Antibodies such as penicillin
- Growth hormone
- Various vaccines for the control of diseases
What do cells need energy for?
- Cell division
- Protein synthesis
- Transmission of nerve impulses
- Muscle cell contraction
What is respiration?
A chemical reaction that happens in all cells. It involves the release of the chemical energy stored in glucose through a series of enzyme-controlled reactions
How is ATP energy created?
From the reaction of ADP + Pi
What is the overall equation of aerobic respiration?
Glucose + Oxygen -> CO2 + Water + 38 ATP
What does glucose split into in respiration?
2 Pyruvate + 2 ATP
What does one pyruvate split into in respiration?
18 ATP + Water + CO2
When does anaerobic respiration take place?
respiration when there is not enough oxygen. Is normally the result of muscle fatigue during excercise.
What is the overall reaction of anaerobic respiration in animals?
Glucose -> 2 ATP + lactate
What are the 2 pyruvate broken down into in anaerobic respiration and where does this take place?
Lactate which will turn into lactic acid and this happens in the cytoplasm.
What is anaerobic respiration in plants also called?
Fermentation
What is the overall reaction of fermentation in plants?
Glucose -> 2 ATP + ethanol + CO2
What does the fact CO2 is released mean for the fermentation reaction?
It is irreversible
What does the fact no CO2 is released mean for anaerobic respiration in animals?
The lactate can be removed by paying back the oxygen debt, meaning that it is reversible.
What can fermentation be used for?
The production of bread, wine and beer.
