Unit C Cycling of Matter in Living Systems : Section 2.0 Flashcards
What are the 7 life processes?
- Intake of nutrients
- Movement
- Growth
- Response to Stimuli
- Exchange of Gases
- Waste Removal
- Reproduction
What are all the organelles in a cell?
- Cell Membrane
- Nucleus
- Cytoplasm
- Chloroplasts
- Vacuoles and Vesicles
- Endoplasmic Reticulum
- Ribosomes
- Lysomes
- Golgi Apparatus
- Mitochondria
What is the cell membrane?
- A protective barrier for the cell
- Allows the transport of needed materials into the cell and waste materials out
Why is the cell membrane important?
- Cell interaction and communication
- Recognition of Molecules
What is the nucleus of a cell?
-The organelle that contains the DNA, the Genetic material of the cell, and directs all cellular material
What is the nucleus (in a cell, not an atom) surrounded by and what does that surrounding thing do?
It is surrounded by the nuclear envelope, which has pores to allow the transport of materials
What is the Cytoplasm of the cell?
-A gel-like substance inside the cell membrane that surrounds it
What does the Cytoplasm contain?
- Contains the nutrients required by the cell to carry out life processes
- Organelles are suspended in the cytoplasm
What is Cytoplasmic streaming?
The movement of organelles and molecules within the cell
What is the cell wall found in?
- Plants
- Bacteria
- Some protists
- And fungi
What is the cell wall?
A rigid frame around the cell that provides strength and support
Where are Chloroplasts found?
They are found in only plants and some protists
What is a protist?
A single-celled organism with a nucleus
What do Chloroplasts contain?
They contain Chlorophyll that produces a green colour
What are Chloroplasts?
-The site of photosynthesis, the process which uses energy from the sun to convert carbon dioxide and water into sugars for the plant’s use and storage
What is the formula for photosynthesis?
6CO2 + 6H2O ——> C6H12O6 + 6O2
What are Vacuoles and Vesicles?
Membrane-bound structures that serve to store nutrients, products of secretion, and fats, depending on tissue type
What does the central vacuole store in plant cells?
Water
What causes a cell to become turgid (firm)?
In plant cells, when fluids enter, the central vacuole swells
What do vesicles do?
Transport substances throughout the cell
What does turgid mean?
Firm
Which organelles are not found in animal cells?
- Cell wall
- Chloroplasts
What is the endoplasmic reticulum?
A series of interconnected tubes that branch from the the nuclear envelope. Materials can be transported through these tubes
What makes Endoplasmic Reticulum rough?
Rough endoplasmic reticulum has ribosomes attached to it which make it not smooth
What is Rough Endoplasmic Reticulum associated with?
Protein synthesis
What is Smooth Endoplasmic Reticulum associated with?
Fat and oil production
What are Ribosomes?
- Dense looking granules formed of two parts
- They may be attached to the endoplasmic reticulum or free in the cytoplasm
What happens inside Ribosomes?
They are the sites where amino acids are assembled into proteins in the process of protein synthesis
What are Lysosomes?
Membrane-bound sacs in the cell where digestion occurs as well as other related activities.
What are the three roles of Lysosomes?
- Defense against invading bacteria
- Destruction of damaged cell organelles
- Controlled digestion of certain tissues during development
What is the Golgi Apparatus?
Flat, disc-shaped sacs involved in secretion
Where does the Golgi receive substance from and what does it do with the substance?
The Endoplasmic Reticulum and it packages those substances for transport out of the cell
What is the Mitochondria?
Rod-like structures where reactions occur to convert chemical energy in sugars into energy the cell can use. The process is called cellular respiration
What is the chemical equation for cellular respiration?
C6H12O6+6O2→6CO2+6H2O+energy
What are the major elements (on the periodic table) making up the structure of plant and animal cells?
Carbon
Hydrogen
Oxygen
Nitrogen
What are the four major organic compounds?
- Lipids
- Carbohydrates
- Protein
- Nucleic acids
What are lipids?
Fats and oils
What are carbohydrates?
Sugars, starches, and cellulose
What is an example of protein?
Muscle fibre
What are nucleic acids?
DNA and genetic material
What are organic materials made out of?
Carbon, hydrogen and oxygen
Why is water called a solvent?
- Many substances can be dissolved in it
- The solvent nature of water provides the environment for all biological reactions inside and outside cells
What are trace elements?
Substances present in tiny amounts that are essential for the health of the cell
What are the trace elements? (context = cell micronutritients)
Magnesium
Zinc
Manganese
Iron
What are the similarities between plant and animal cells
- Cell membrane
- A cytoskeleton made of proteins and lipids
- Have DNA made up of sugars, nitrogen containing compounds, and phosphate
What is a cytoskeleton?
Network of fine protein fibres, also lipids, that support cells that contain a nucleus (plant and animal cells included)
What are the differences between plant and animal cells?
- Animal cells have centrioles
- Animal cells have specialized compounds
- Plant cells have cell walls
- Plant cells have chlorophyll in the chloroplast, animal cells do not have chlorophyll nor do they have chloroplasts
- Plants store energy in the form of oil (they also store as starch but that is not a difference since animal cells store energy in the form of starch)
- Plants have a large central vacuole
What are centrioles?
Paired structures found in animal cells (not in plant cells) that are important for the process of cell division
How do plant cells store energy?
In the form of starch or oils
What does the cell membrane contain?
A Phospholipid bilayer
What is a Phospholipid bilayer?
A double layer of lipids that each have a phosphate group attached.
How does a Phospholipid bilayer work?
The phosphates face out into the watery fluids on either side of the membrane while the lipids face toward each other in the inner part of the membrane. Proteins are suspended in it. Some have sugar molecules attached
What is the Fluid-mosaic model?
A description of the arrangement of protein molecules in the fluid double layer of phospholipids that make up the cell membrane
Do animals have cell walls?
No
What are the main things that cells transport?
Gases, nutrients and wastes
What are the 4 points to the particle model of matter?
- All matter is made of particles but the particles in different substances may be different in size and composition
- The particles of matter are constantly moving or vibrating
- The particles of matter are attracted to one another or are bonded together
- Particles have spaces between them that are smallest in solids
What is diffusion?
The natural movement of particles from areas of high concentration to area of low concentration
What is equilibrium? (Context =concentrations of substances)
When particles maintain an overall balance and even distribution.
How can the rate of diffusion be increased?
By adding energy and increasing molecular movement
What is the rate of diffusion?
The relative movement of a particle in response to concentration gradient
What does the concentration gradient determine?
The direction in which water or solutes move
What type of transport is diffusion?
Passive transport because no energy is required for it to occur
What is passive transport?
Movement of substances along a concentration gradient. The movement does not require ATP
What type of membrane is the cell membrane and why?
Selectively permeable because it allows certain particles to pass through it, but not all particles
What is the passage of materials through the cell membrane determined by?
- Size of molecules / small enough to fit through the pores
- Their charge
- And whether they are soluble in lipids
What is osmosis?
When water molecules move across their concentration gradient from an area of high water concentration to an area of low water concentration
What type of transport is osmosis?
Passive transport
What is a hypertonic solution?
A solution that has a higher concentration of solutes (outside of the cell) than that in the cell
What is a hypotonic solution?
A solution that has a lower concentration of solutes (outside of the cell) than that in the cell
What is an isotonic solution?
A solution that has the same concentration of solutes as that in the cell
How does turgor pressure affect a plant?
It supports the plant’s structure
Where does water go in a hypertonic solution?
Water will move out of the cell because of the high concentration of solute outside of the cell
Where does water go in a hypotonic solution?
Water will move into the cell because of the high concentration of the solute in the cell
Hypotonic refers to less concentration of solute on the outside of the cell. So the water moves in to the cell to equalize the concentrations in and out of the cell.
What substances can pass through the lipid bilayer by diffusion?
Only substances that are soluble in lipids
What substances use facilitated diffusion?
Substances that are soluble in water but not in lipids
What are the two types of proteins that make facilitated diffusion happen?
Channel proteins and Carrier proteins
How do channel proteins work?
They create pores or channels through which small water-soluble particles are able to move. They move in response to the concentration gradient.
A channel protein isa protein that allows the transport of specific substances across a cell membrane. Remember that a protein is a biological macromolecule made up from a menu of 20 different amino acids and that the sequence of those chains determines the specific shape and function of the protein.
How do carrier proteins work?
They have the ability to attach to larger molecules that are not able to diffuse across the membrane.
They change shape and physically move the molecule across the membrane
Why is it called facilitated diffusion?
Because the movement is in response to the concentration gradient but needs the presence of a protein facilitator. Carrier proteins and channel proteins are facilitators.
What type of transport is facilitated diffusion?
Passive transport because no added energy is needed for the process to occur
What is Active Transport?
The movement of substances from an area of low concentration to an area of high concentration against the concentration gradient
What does Active transport require?
Energy
Where does the energy for active transport come from?
- From cellular respiration in the mitochondria.
- The cytoplasm and the mitochondria break down glucose and produce ATP
Why would a cell need to use Endocytosis or Exocytosis?
Some molecules are too large to pass through the cell membrane
What organelle does a cell use to perform Endocytosis or Exocytosis?
Vesicles, they are similar in structure to vacuole but are usually small and temporary
What is Endocytosis?
To take particles or molecules in the cell by the formation of a vesicle from the cell membrane
What is Exocytosis?
The release of molecules from a vesicle that fuses with the cell membrane to export molecules from the cell
What type of transport are Endocytosis and Exocytosis?
Active Transport
What are membrane technologies?
Research and development based on the cell membrane
Where are recognition proteins in the cell?
They are embedded within but stick out on the outside
What are recognition proteins?
Protein molecules protruding from the cells that allow communication between cells
What are recognition proteins for?
They allow cells to recognize one another
What are receptor proteins?
Specialized molecules on the surface of the cell to which messenger molecules can bind
What do receptor proteins do?
They bind specifically with certain molecules to bring them into the cell by endocytosis or change shape in order to communicate with the cell.
What do the sugar groups on some receptor proteins do?
They make specific binds and allow the cell to identify a particular bacteria or virus
Describe the lock and key scenario discovered to prevent disease
The process would work to block or close off the receptor proteins in human cell membrane
What is a negative to current cancer treatments?
They are unable to single out specific cancer cells so sometimes they target healthy cells
What are Liposomes?
fluid filled sacs surrounded by the phospholipid bilayer. The bilayer is identical to the cell membrane in human cells
What are Liposomes used for?
The delivery of drugs to infected body tissue
How big are Liposomes?
Microscopic, about 1/1000 the diameter of human hair
How do Liposomes work?
- Water trapped on the inside can hold water-soluble medications while the membrane layer is able to hold fat-soluble medications.
- The tiny sacs are introduced into the bloodstream and circulate throughout the body
- Liposomes attach to infected cells and deliver the mediation
How do Liposomes assist in gene therapy?
- DNA is contained inside the Liposome
- A molecule on the Liposome surface fits onto certain cancer cells to recognize the target and correct cells
What is insulin?
A protein that binds to a protein on the cell membrane, allowing glucose to enter the cell by facilitated diffusion
Where is insulin produced?
In the pancreas
How do insulin hormones work?
- It is secreted into the bloodstream and binds with membrane at a distance from the point of secretion
- The complex formed between the hormone and the target cell triggers the target cell to undergo a particular process
How is insulin released from the pancreas?
By Exocytosis
How does the pancreas detect glucose?
It has specialized channels that detect it in the bloodstream
What happens when the pancreas detects glucose in the blood?
-It initiates the excretion of insulin into the blood
What does insulin do?
-Binds to the receptor proteins of tissues including, liver, muscle, and fat
What does the binding of insulin do?
Stimulates the rate of movement of glucose into the cells through facilitated diffusion using a carrier protein
What is glucose in the body used for?
Used to produce energy or is stored as a future source of energy
How is glucose put into the cell?
Facilitated diffusion
What are the 2 types of dialysis?
Peritoneal dialysis and Hemodialysis
How is kidney failure treated?
With dialysis
What principals are dialysis based on?
Diffusion and Osmosis
What is the purpose of dialysis?
To rid the blood of toxins, wastes, and excess fluids produced by the cells of the body
Where do waste products in the body go?
In the peritoneum which lines the abdominal cavity
How does peritoneal dialysis work?
- A plastic tube is inserted into the abdomen.
- Sterile dialysate fluid is pumped into the abdominal cavity and removes waste from the peritoneum by diffusion
What does dialysate consist of?
A mixture of water, glucose, and certain substance the body needs
How does diffusion work in peritoneal dialysis?
The dialysate has no toxin present so the concentration in the blood is higher. The toxin go from high concentration in the blood to low concentration in the fluid
Where do the toxins come from in peritoneal dialysis?
The intestines are surrounded by a membrane called the peritoneum the waste from the blood is passed into the cells of this fluid
How does hemodialysis work?
The blood is removed from the body, cleaned using special machines and returned to dialysis
What is the downside to hemodialysis?
The patient must go to a health clinic and must remain stationary
What is desalination?
The process of removing salt from seawater to make it suitable for drinking
What reverse osmosis?
The movement of water through a semi-permeable membrane from the are of a high concentration of a solute to a low concentration of a solute
How will it affect the transport of substances into the cell if it becomes larger and increases in volume?
- More molecules will have to be transported across the cell surface to take part in the cells function
- The distance any molecule has to travel from the cell surface increases
What happens if a cell increases in size?
Its surface area to volume ratio decreases
What does a cell need for efficient transport?
The cell must have a large surface area in relation to its volume. The greater surface area to volume ratio the more efficient it will be
What happens if the surface area of a cell is very little?
The opportunities for intake of needed material and the expulsion of waste is very limited
What does Xylem in plants do?
Delivery of water from the roots to all parts of the plants
What does the Phloem in plants do?
Distributes sugars throughout the plants according to conditions
What do capillaries do?
Transport blood to bring nutrients and waste
