Unit 1 Flashcards
How do living things stay alive?
Define the meaning of a cell.
The basic building block that makes up all living organisms on earth.
Name characteristics of prokaryotic cells.
- Lacks membrane bound organelles
- Lack membrane bound nucleus so DNA is found in the nucleoid.
- Lacks mitochondria
- Has extra DNA information called plasmids.
- Members of Kingdoms Bacteria and Archaea
Name characteristics of eukaryotic cells
- Has membrane bound organelles suspended in cytosol
- Member of Kingdoms Anamalia, Plantae, Protista, and Fungi
Describe the average range of cell size.
2um (bacteria) to 10um (small prokaryote) to 100um (large prokaryote)
Describe the role of the plamsa membrane
- Separates the cell from other cells.
- Allows or prevents the transferal of substances into or out of the cell.
Describe cytoplasm
-What is contained inside the cells including cytosol and organelles.
Describe the role of the nucleus
- Contains DNA in the form of chromosomes.
- Coordinates cell activity.
Describe the role of the nucleolus
- Contains RNA
- The site of ribosome synthesis
Describe the role of the mitochondria
-Creates energy for cells using respiration
Describe the role of ribosomes
-Synthesise proteins using amino acids
Describe the role of the endoplasmic reticulum
- Allows proteins and other substances to move around the cell
- Creates vesicles for transportation
Describe the difference between Rough Endoplasmic reticulum and Smooth Endoplasmic reticulum
- Rough endoplasmic reticulum is lined with ribosomes, which allows the proteins synthesised to be modified within the endoplasmic reticulum and then trasported elsewhere immediately.
- Smooth endoplasmic reticulum is not lined with ribosomes and transports proteins, synthesises lipids and help make plasma membranes.
Describe the role of the Golgi Apparatus
The Golgi apparatus modify and package substances in a vesicle before secreting them out of the cell.
Describe the role of Lysosomes
Lysosomes are formed by the Golgi Apparatus that contain highly acidic digestive enzymes to break down old organelles and substances into amino acids so that they can be reused.
Describe the components and the role of the Cytoskeleton
The cytoskeleton is made up of microtubules and microfilaments and supports the shape of the cell. The components of the cytoskeleton can easily reassemble and disassemble themselves.
Describe the significance of microtubules.
Microtubules are hollow and act as scaffolding, but make a kind of railing system for organelles to travel around in the cytoplasm. This is called cytoplasmic streaming.
Describe the role of centrioles.
Centrioles make and organise microtubules. The are important in cell division, as they duplicate before to assist the division by creating groups of microtubules for the chromosomes to attach to.
Describe the role of plastids
Plastids store and produce food using photosynthesis
Describe chloroplasts
Chloroplasts contain a green pigment called chlorophyll which allows them to harness the energy of the sun and create energy using photosynthesis.
Describe chromoplasts
Chromoplasts contain a red or yellow pigments called carotenoid which allows them to harness the energy of the sun to photosynthesise
Describe Leucoplasts
Leucoplasts have no pigments and do not photosynthesis.
Describe the role of vacuoles
The vacuole stores water. It takes up a large amount of the cytoplasm in plant cells. The larger the vacuole, the stiffer the cell.
Describe the importance of SA:V ratio
The surface area to volume ratio determines how well a cell will survive. A cell with a low SA:V wiill be less likely to survive as there is not enough volume or surface area to gain nutrients and remove waste. A cell with a large SA:V will be more likely to survive because there is a large surface area to absorb nutrient while being able to remove waste efficiently.
Describe compartmentalisation
To make the SA:V ratio larger, eukaryotic cells bind organelles with a membrane to combat rising volume levels as it grows.
Compare the SA:V between spherical and rectangular cells.
Spherical cells have a smaller SA:V as a sphere has the least amount of SA for the V it encloses. Rectangular cells have a larger SA:V because the SA is larger compared to the V.
Describe what makes up the plasma membrane
The plasma membrane is made of a phospholipid bilayer, two layers of a phosphate head with fatty acid tails, with the tails pointing towards each other.
Describe the difference between a permeable membrane and a selectively permeable membrane.
A permable membrane allows all substances through. A selectively permeable membrane controls with substances can come in or out of the cell.
Describe the characteristics of a phospholipid.
The phosphate head is hydrophilid, or water soluble. The lipid tails are hydrophobic, or non water soluble. Because the tails are repelled by water they always end up poiting to each other.
Describe the role of transport proteins
Transport proteins allow certain substances through the plasma membrane.
Describe the role of receptor proteins
Receptor proteins respond to hormones or other substances that change a cells activities.
Describe the role of recognition proteins
Recognition proteins allow the immune system to differentiate between its own cells and invader cells.
Describe the role of adhesion proteins
Adhesion proteins link cells together to maintain the 3D structure and regular functioning of tissues.
Define passive movement
Passive movement is movement of substances that requires no energy
Define simple diffusion
Simple diffusion is the net movement of particles from an area of high concentration to an area of low concentration, or along the concerntration gradient until equilibrium is reached.
Define facilitated diffusion
Facilitated diffusion is the the same as simple diffusion except aided with either channel or carrier proteins for particles that cannot pass through the plasma membrane
Describe the role of a channel protein
Channel proteins bind to the plasma membrane and form a small tunnel that allows particular particles to diffuse through them.
Describe the role of a carrier protein
Carrier proteins bind to the the plasma membrane and change shape to allow certain particles through.
Describe osmosis
Osmosis is simple diffusion but specifically for water. Osmosis is the diffusion of water across a selectively permeable membrane from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration) until equilibirum is reached.
Define isotonic
The fluid outside of the cell is isontonic when ift has the same concentration as the fluid inside the cell.
Define endocytosis
A type of bulk transport where sunstances are taken into the cell.
Define exocytosis
A type of bulk transport where substances are taken outside of the cell
Define pinocytosis
A type of of bulk transport where liquid substances are moved into and out of the cell
Define phagocytosis
A type of bulk transport where solid substances are moved into and out of the cell
Define bulk transport
A kind of transport that uses energy to transport large amounts of substances into and out of a cell using a vesicle.
Define active transport
The net movement of a substance against the concentration gradient from a place of low concentration to high concentration that requires the use of ATP.
Explain the purpose of cholesterol in the plasma membrane.
Cholesterol gives the plasma membrane more stength and support so that when in expands of contracts it does not break.
Explain the purpose of glycolipids and glycoproteins in the phospholipid bilayer.
Glycolipids and glycoproteins are involved in cellular communication, acting as markers and receptors. Receptors interpret chemical messages like hormones and markers identify the cell.
Define plasmolysis
Plasmolysis is the shrinking of the plasma membrane in a plant cell because of net water loss.
Define crenation
Crenation is the shrinking of an animal cell’s plasma membrane because of net water loss.
Define haemolysis
Haemolysisis when a red blood cell ruptures because of net water gain.
Define autotroph
An autotroph is an organism that creates its own glucose..
Define heterotroph
A heterotroph is an organism that must eat other organisms to gain a source of glucose
What is the overall reaction of photosynthesis?
6CO2 + 12H2O ——-> C2H12O6 + 6O2 + 6H2O
(light & enzymes)
I dentify the organelle in which photosynthesis takes place.
The chlorophyll-rich chloroplast
Explain the light dependent cycle of photosynthesis
The light dependent stage
- Requires light
- Takes place in the thylakoids (in the granum in the chloroplast)
- Converts H2O and ADP+Pi into H+, O2 gas (released) & ATP
Explain the light independent cycle of photosynthesis
The light independent stage
- Requires no light
- Takes place in the stroma (located in the chloroplast)
- Converts CO2, H+ & ATP into C6H12O6, ADP+Pi & H20
State the overall equation for Cellular Respiration
6O2 + C6H12O6 —–> 6CO2 + 6H2O
^
ADP+Pi —> 36ATP
Which organelle does respiration occur in?
Cellular respiration occurs in the mitochondria
Explain the process of glycolysis.
Glucose (C6H12O6) is broken down into pyruvic acid (3C each)
It takes place in the cytosol of a cell.
It produces 2 ATP
What is the purpose of respiration?
Respiration is required to produce energy for transporting substances, synthesising proteins, metabolising and more.
Explain the process of fermentation
Fermentation occurs only in plant cells when there is no oxygen. After glycolysis has occured, the pyruvic acid is broken down into ethanol (alcohol) and CO2. This process creates 2 ATP. Ethanol is toxic
Explain the process of anaerobic respiration.
Anaerobic respiration occurs only in animal cells when there is no oxygen. After glycolysis has occured, the pyruvic acid is broken down into Lactic acid. This process create 2 ATP. Lactic acid is toxic.
Why does anaerobic respiration occur
Anaerobic respiration occurs when there is no oxygen is available, so the Krebs Cycle and Electron transport chain cannot occur. The NAD molecules used to transport the H+ must return to the cytosol of the cell or else glycolysis cannot continue to occur. Anaerobic respiration allows the NAD molecules to return to the cytosol.
Describe the palisade mesophyll
The palisade mesophyll are found close to the top of the leaf, under the epidermis. They are tightly packed together and are packed with chlorophyll to photosynthesise.
Describe the spongy mesophyll
The spongy mesophyll are found underneath the palisade mesophyll. They have gaps so th
What are the structural differences between the xylem and the phloem
The xylem is made of elongated hollow dead cells that are made water impermeable by lignin.
The phloem are made of several living cells including sieve cell, specialised cells for transport that have perforated end so that cytoplasm is shared between cells. Companion cells provide energy for the transport.
What are the structural differences between the xylem and the phloem
The xylem is made of elongated hollow dead cells that are made water impermeable by lignin.
The phloem are made of several living cells including sieve cell, specialised cells for transport that have perforated end so that cytoplasm is shared between cells. Companion cells provide energy for the transport.
What is the function of peroxisomes
Peroxisomes contain enzymes that detoxify materials in the bloodstream.
Chlorophyll absorbs … light most efficiently and … light least efficiently
Green, blue
Where does the light dependent stange of photosynthesis take place?
The light dependent stage takes place in the grana/thylakoids.
What is the importance of ribosomes in chloroplasts
Ribosomes synthesise proteins to produce the enzymes needed for photosynthesis, assist in the production of chlorophyll and make the membranes of the chloroplasts.
What are the inputs and outputs of the light dependent stage of photosynthesis
Inputs include water, NADP and ADP+Pi
Outputs include oxygen, ATP and NADPH
Where does the electron transport stage of aerobic respiration occur?
Electron transport occurs in the cristae of the mitochondria
What happens during the electron transport stage of respiration?
Electrons are passed along a series of cytochromes. Oxygen captures electron, which are combined with hydrogen. Carrier molecules give up hydrogen as it is passed along. ATP and water is produced.
