Cells Flashcards
What are cells?
Cells are the biological units that are the building blocks of life
State the cell theory
The cell theory states: “all living things are composed of one or more cells and all cells come from pre-existing cells”
How many millimetre make a micron?
1mm = 1000um
What is the equation to convert millimetres into microns?
a x 10^-3
What are the two different types of cells?
Eukaryotes
Prokaryotes
What are eukaryotes?
Cell with a nucleus and defined membrane and other organelles
Eg. Animals and plants
What are prokaryotes?
Without a nucleus, doesn’t have clearly defined components
Eg. Monera (bacteria)
What are the 14 main organelles in a eukaryotes cell?
Cell membrane Cytoskeleton Cytoplasm Nucleus Ribosomes Endoplasmic reticulum (smooth and rough) Golgi body Vesicles Lysosomes Mitochondria Centrioles
Plant organelles:
Cell wall
Chloroplast
Vacuole
What are the 10 main organelles of a prokaryotic cell?
Capsule Cell wall Plasma membrane Bacterial flagellum Ribosomes Chromosomes (DNA) Pili Plasmid (DNA) Nucleoid (nuclear zone/cytoplasm) Mesosome
What is the difference between prokaryotic cells and eukaryotic cells?
Prokaryotic cells experience difficulty performing several different functions at the same time, due to their lack of membrane-bound organelles, this limits their versatility. And a lack of a nuclear membrane
Eukaryotic cells have membrane-bound organelles in seperate compartments.
What is the job of cell membrane?
It acts like the border security, It is a semi-permeable membrane, that allows only certain substances in and out
What is the cell membrane made out of?
Lipids and proteins
Describe how the phospholipids work
They have two parts, a hydrophilic head (water loving) and a hydrophobic tail (water-fearing). Because of this arrangement it creates a two layer structure, as water surrounded the cell, it is a called a phospholipid bilayer.
What do proteins do in a cell membrane?
They can act like channels, signal receptors, or like the border security only letting certain things in and out. Some can just be found stuck on the side
What is the nuclear membrane?
It is a double layered membrane that has pores to allow substances in and out.
Molecules are constantly changing positions so it is fluid
What is the cytosol?
The semi fluid substance in the cytoplasm
What is the job of the nucleus?
It acts as the Brain.
It houses the cells genetic material (DNA)
It is made up of a nuclear envelope and nucleolus
What is the job of the cytoskeleton?
It acts as the skeleton of the cell. 💀
It helps maintain the cell’s shape, it is attached the cell membrane and holds the organelles in position. It constrains threadlike microfilaments and microtubules, and intermediate filaments.
What is the nucleolus?
A dark spot inside the nucleus, that creates ribosomes.
What is the job of the cytoplasm?
It is a jelly like substance that all organelles float in.
It is made up of cytoskeleton and cytosol
What is the job of ribosomes?
It acts as a factory, where amino acids are linked together to synthesise proteins, according to instructions from the nucleus
What is the job of the rough endoplasmic reticulum?
It acts like a chauffeur to other organelles and proteins. They are a system of flatten parrallel sacs called cisterns, studded with ribosomes. It transports materials such as proteins into small vesicles within and between cells.
What is the job of the smooth endoplasmic reticulum?
Acts as the sumo. Similar to the rough ER expect with no ribosomes. It is involved in the formation and transportation of lipids, steroids and hormones. It also protects the cell from harmful compounds. Eg. Drugs
What is the job of the lysosome?
It acts as the garbage man. It is a type of vesicles that contains enzymes that split complex chemical compounds into simpler versions, including getting rid of organelles that no longer function properly.
What is the job of the Golgi body?
It acts as the postman. It is a stack of flatten vesicles. It receives vesicles from the ER, and packages it to go out the cell, this process is called exocytosis.
Lipids and proteins are modified and sorted, ‘like a processing station’
What is the nucleolus made of?
Proteins and nucleic acids
What is the job is the centrioles?
They act as tug of war experts. They assist with cell division, through using their spindle fibres to pull apart chromosomes, through a process called mitosis.
What are the three organelles that plants cells have that animals do not?
Cell wall
Vacuole
Chloroplast
What is the job of the cell wall?
It acts as the wall, it protects,supports and helps keep the shape of the cell.
And if the vacuole is filled with too much water the cell with not burst, because of the wall, and if the cell is dehydrated it will not shrivel up.
What is the job of the vacuole?
It acts as the sack, that stores and digests water and oils for the plant and maintain turgor pressure
What is the job of chloroplast?
It acts as a sunbather. Found in mostly leaf and stem cells, has an inner and outer membrane, filled with semi-fluid material called stroma; contains flat sacs called thylakoids. It carries out photosynthesis to create glucose for the plant
What are the 5 structures mitochondrion are made of?
Cristae, stalked particles on the surfaces of the cristae, outer and inner membrane and a matrix
What are organelles?
Specialised structures living within a cell that have a specific function
What are the 8 structures chloroplast are made of?
An outer membrane an inner membrane stroma (space between the thylakoids) granum (stack of thylakoid) lamella (connects the granum) lumen (inside the thylakoid) thylakoid membranes starch grains.
What is the equation to find FOV for high power in microscopes?
FOV(HP)= FOV(LP) x (LP mag/HP mag)
State 3 types of proteins and their function.
Enzymes- biological catalysts
Hemoglobin- transporting oxygen in blood
Transport proteins- proteins that are in the membrane that act as transporters of materials
What is the difference between microtubules and microfilaments?
Microtubules are hollow and have a large diameter and microfilaments are not hollow and have a small diameter.
Both are made of proteins
What are cristae?
Fold in the inner membrane of the mitochondria, they increase the surface area so there is more space for the series of compounds that make up electrons transport system to speed up the production of ATP.
What are thylakoids?
Flatten sacs inside the chloroplast, contains the chlorophyll and helps absorb sunlight in order for photosynthesis to occur.
What are stroma thylakoids?
Open space in chloroplasts that is the colourless fluid surrounding the grana. The location of chloroplast DNA, chloroplast ribosomes and molecular processes.
What are plastids?
Double membraned cell
Eg. Mitochondria, chloroplast
What are plasmid?
Small circle of DNA, found in prokaryotes, used to exchange DNA between bacterial cells and is very useful for genetic engineering.
What is the job of the mitochondria?
It acts as the powerhouse of the cell. It has an inner and outer membrane and many folded membranes inside called cristae. It breaks down food and release it as energy. During cellular aerobic respiration (breaking down of glucose), the mitochondria produces ATP for molecules, that provides energy for all the cell.
What are mesosomes?
A tightly-folded region of the cell membrane containing all the membrane-bounded proteins required for respiration and photosynthesis.
What is the cell wall of prokaryotes made of?
Made of murein which is a glycoprotein (protein with an attached carbohydrate.
What is the capsule?
thick polysaccharid layer outside the cell wall.
- Used for sticking cells together
- food reserve
- protection
What drives the Flagellum?
H+ gradient across the membrane, drives the rating helical-shaped tail used for propulsion.
What do the stalked particles on the crust do?
Site of ATP synthesis
What is metabolism?
Describes the sum total of the physical and chemical processes by which cell components transform matter and energy needed to sustain life
