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.