Cell Structure, Membrane Transport + DNA and the Production of Proteins Flashcards
What is the function of the cell wall and which types of cells are they found in?
The cell wall is found in the plant, fungal and bacterial cell
It’s function is to provide support to cells
What is the function of the mitochondria and which types of cells are they found in?
The mitochondria is found in animal, plant and fungal cells.
It is the site of aerobic respiration
What is the function of chloroplasts and which types of cells are they found in?
Chloroplasts are only found in some plant cells (ie: in green plants)
It’s function is that it contains pigment chlorophyll which traps light energy from the sun and needed for photosynthesis
What is the function of the cell membrane and which types of cells are they found in?
The cell membrane is found in all cells
It’s function is to control the movement of substances moving in and out of the cell
What is the function of the cytoplasm and which types of cells are they found in?
The cytoplasm is found in all cells
It’s function is where all chemical reactions occur
What is the function of the vacuole and which types of cells are they found in?
The vacuole is found in plant and fungal cells
It’s a fluid filled sac which contains water, sugars and salts
What is the function of the nucleus and which types of cells is it found in?
The nucleus is found in animal, plant and fungal cells.
It controls cell activities and contains genetic information
What is the function of the ribosomes and which types of cells are they found in?
The ribosomes are found in all cells
It’s the site of protein synthesis
What is the function of plasmids and which types of cells are they found in?
The plasmids are only found in bacterial cells
It is small circular DNA
What is the function of cellulose and which types of cells are they found in?
Cellulose is only found in plant cells
It is a structural carbohydrate present in the cell wall
Fill in the blanks: A bacterium has one chromosome in the form of a complete circle and one or more smaller circles called………?
Plasmids.
What are the chromosomes and plasmids made up of?
DNA.
What type of fungus is yeast?
A uni-cellular fungus.
Look at all the cells. Be able to identify and name all organelles in the cell. Do this for each cell.
Rate the card as to how well you named the organelles of the cell.
What are plant cell walls made out of?
Cellulose.
Do cell walls in fungi and bacteria contain cellulose?
No. They are made out of different types of carbohydrate.
How do yeast cells grow?
Yeast grows by increasing the number of yeast cells through asexual reproduction.
How do yeast cells multiply?
They multiply by budding.
Name 5 structures found both in animal and plant cells.
Nucleus, cytoplasm, mitochondria, cell membrane and ribosomes.
Name three structures found in plant cells but not in animal cells.
Chloroplasts (only in green plants), vacuole, cell wall.
Name one structure only found in green plant cells.
Chloroplasts.
What organelle (cell structure) carries out protein synthesis?
Ribosomes.
Which organelle is responsible for providing most of a cell’s energy requirements.
Mitochondria.
What solution is commonly used to stain cells?
Iodine solution.
How is total magnification calculated?
Eyepiece lens x Objective lens
Example: Calculate the total magnification with the following measurements:
Eyepiece lens: 20x
Objective lens: 40x
Total magnification = 800x
(SHOW YOUR WORKING)
Example: Find the measurement of the eyepiece lens with the following measurements:
Objective lens: 10x
Total magnification: 400x
Eyepiece lens = 40x
(SHOW YOUR WORKING)
How to you convert mm to µm?
To convert mm to µm you x1000
How do you convert µm to mm?
To convert µm to mm you ÷ 1000
How do you calculate the average length of one cell?
Diameter ÷ cells across
Example: Calculate the average length of one cell using the following measurements, give answer in micrometres:
Cells across: 4
Diameter: 1mm
Answer: 250 µm
(SHOW WORKING AND CONVERSION)
How do you calculate the average breadth of one cell?
Diameter ÷ cells from the top to bottom
Example: Calculate the average breadth of one cell using the following measurements:
Diameter: 2mm
Cells from top to bottom: 10
Answer: 200 µm
(SHOW ALL WORKING AND CONVERSIONS)
What is a cell?
Basic unit of all living things.
What is a bacteria?
A single-celled organism which doesn’t have a nucleus.
What is a fungi?
Single-celled organism containing nucleus, cell wall and vacuole.
What is a circular chromosome?
Genetic material found within the cytoplasm of bacterial cells.
How are proteins denatured?
They are denatured with acid + high temperatures.
How are phospholipids destroyed?
They are destroyed by alcohol.
What are the two main parts that the cell membrane is made up of?
Phospholipids and proteins.
What do the phospholipids make up in the cell membrane and what can they do?
They make up the membrane fluid.
They are able to move.
Where are the proteins found in the cell membrane?
They are found within the membrane and on each surface.
What can the cell membrane described as and what does it mean?
The cell membrane is described as being ‘selectively permeable’, which means it controls what substances can move in and out of the cell. If it is small enough, it can move in and out. If it is too large, then the substance has the stay where it is.
What are examples of substances can pass through the cell membrane?
Amino acids, glucose, fatty acids, water, oxygen, carbon dioxide.
What are examples of substances cannot pass through the cell membrane?
Proteins, cells, starch, fats.
What is the definition of a concentration gradient?
A concentration gradient means that the concentration of a particular substance is greater on one side than the other.
What is the definition of diffusion?
Diffusion is the movement of molecules of a substance down a concentration gradient, from a region of higher concentration to a region of lower concentration until the concentration becomes equal.
It is a form of passive transport which means that this process requires no energy.
What substances enter the cell from diffusion and how?
Glucose and oxygen enter the cell from a higher concentration outside the cell to a lower concentration inside the cell.
What substance leaves the cell during diffusion and how?
Carbon dioxide leaves the cell from diffusion from a higher concentration inside the cell to a lower concentration outside the cell.
Why is diffusion important to cells?
They gain raw materials (oxygen and glucose) for respiration
They remove harmful waste products; carbon dioxide
What is Osmosis?
Osmosis is the movement of water from a higher water concentration to a lower water concentration across a selectively permeable membrane
How can you make results of an experiment more reliable?
Repeating the experiment and taking an average of your results.
What is the condition of a plant cell which has gained water by osmosis, and what will the cell look like?
It is called a turgid cell. The cell contents appear swollen and push against the cell wall.
What is the condition of a plant cell which has lost water by osmosis, and what will the contents of the cell look like?
It is called a plasmolysed cell. The vacuole and cytoplasm will appear shrunken and the cell membrane will have pulled away from the cell wall
What happens to an animal cell that gains water from osmosis?
It bursts
What happens when an animal cell loses water from osmosis?
It shrinks
Why do animal cells burst when it gains water from osmosis?
Plant cells have a cell wall whereas animal cells have no cell wall
What is the definition of chromosomes?
Chromosomes are structures which contain genetic information
There are 46 (23 pairs) of these in a cell.
What is the definition of a gene?
Genes are a section of a chromosome and carry the code to make one protein
They have different forms called alleles
What is the shape of DNA?
Double stranded helix
What are the names of the bases of DNA and what do they pair with?
The bases are Guanine (G), Cytosine (C), Thymine (T) and Adenine (A)
Guanine (G) pairs with Cytosine (C)
Thymine (T) pairs with Adenine (A)
What do the bases of gene codes for a protein determine?
The sequence of the bases determine the order of amino acids which in turn determines the structure of the protein and its function
What is mRNA?
Molecule that carries a complementary copy of the genetic code from the DNA in the nucleus.
What are base pairs?
Bonding of complementary bases in DNA molecules, ie: G pairs with C and A pairs with T
What are amino acids?
The sub units of a protein and are arranged in sequence to make a protein molecule.
What are proteins?
Molecules that carry out many cellular functions, made from amino acids.
What is DNA?
Substance that forms chromosomes and contains genetic information
Describe the formation of a protein. (Starting from DNA)
DNA > mRNA > ribosomes > amino acids > protein
What is DNA made of?
Bases
What needs to happen for protein synthesis to occur?
A complementary copy of genetic code must be made and contained in the mRNA.
The mRNA is then transported from the nucleus to the ribosome for protein synthesis.
What is haemoglobin?
Red pigment that carries oxygen around the body
What are antibodies?
Produced by white blood cells and protects body from pathogens
Hormones
Chemical messengers. Eg: insulin, testosterone, oestrogen, adrenaline
What are enzymes?
Speed up chemical reactions. Eg: amylase, catalase, phosphorylase
What are transport proteins?
They help the movement of molecules. Eg: membrane protein
What are structural proteins?
Provide shape and support to an organism. Eg: collagen, keratin, actin, myosin.
What is active transport?
Active transport is the movement of ions moves a across a cell membrane, against a concentration gradient from a lower concentration to a higher concentration. This process requires energy to transport the substance. Substances cross the membrane through a protein molecule.
What is an example of active transport?
Sodium/Potassium pump, where proteins in the membrane pump sodium ions out the cell and potassium ions in the cell.
