Cells Flashcards
What is abiogenesis?
A false theory that says living things can come from non-living matter: spontaneous generation.
What is a theory?
Predictions based on statements that explain observations, which can be tested experimentally.
What is biogenesis?
The theory that all living things come from other living things.
Who performed the raw meat and maggots experiment? What did it prove?
Francesco Redi (1626-1697). It proved that the larvae is produced from flies landing on it when exposed to the atmosphere.
What do all cells contain?
Cell membrane, cytoplasm, genetic material, ribosomes.
What is the primary difference between prokaryotic and eukaryotic cells?
Prokaryotic lack nuclei, eukaryotic has genetic material.
Two types of prokaryotes are…?
Eubacteria and archaebacteria.
Which type of bacteria is more likely to be found in an extreme environment?
Archaebacteria.
Plants cell walls contain…
Cellulose.
Fungi-like protists cell walls contain…
Chitin.
Archaebacteria cell walls contain…
Pseudopeptidoglycan.
Eubacteria cell walls contain…
Peptidoglycan.
Fungi and fungi-like protists cell walls contain…
Chitin.
Which type of cells don’t have cell walls?
Animals.
Plasma membranes have…
Phospholipids: a phosphate and a fat molecule.
True or false: the lipid bilayer has the lipid tails facing outwards.
FALSE. The phosphate head is on the outside.
What is the function of the lipid bilayer?
Controls what enters or leaves the cell (it can open and close).
What controls which molecules enter the lipid bilayer?
Proteins.
Which part of the lipid bilayer identifies the type of cell trying to enter?
The carbohydrates. \ / \ / || ^^^^^^
What does every solution contain?
A solute and a solvent.
What is diffusion?
Movement of molecules from high concentration to low concentration.
[mole.]^ —> [mole.]\/
It is what carries oxygen to human cells.
Kinetic energy of the molecules is measured by what three conditions?
Temperature, pressure and difference in concentration.
What is osmosis?
The diffusion of water across a selectively permeable (semipermeable) membrane.
[water]^ —> [water]\/
What is a hypertonic solution?
Higher concentration of solute.
What is a hypotonic solution?
Higher concentration of water. HypEAUtonic.
What is a solvent?
A substance that dissolved a solute.
True or false: diffusion only goes from high to low concentration.
TRUE. Ex: 100% —> 95%
What is an isotonic solution?
Two substances of equal concentration.
What is passive transport?
The movement of molecules across the plasma membrane without the use of energy (ATP).
What is facilitated diffusion?
Membrane proteins that allow the passage (diffusion) of large molecules.
What is active transport?
Movement of molecules across the plasma men ran using energy. Molecules are moved from a low to high concentration.
In what order does cell specification occur?
Cells > tissue > organ > organ system > organism
The cell theory states…
All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.
What procedures need to be taken to observe cells under electron microscopes that require them to be dead to view?
Preserved and dehydrated.
What are organelles?
Structures in eukaryotic cells known as little organs.
What is the function of the cytoplasm.
It is the portion of the cell that is outside of the nucleus.
Which organelle contains nearly all the cells DNA and with it the coded instructions for making proteins and other important molecules.
The nucleus.
Which part of the nuclear envelope allows material to move into and out of the nucleus?
The nuclear pores.
What is the granular material you can see in the nucleus?
Chromatin. It is DNA bound to proteins most of the time chromatin is spread throughout the nucleus.
When a cell divides what does chromatin condense into?
Chromosomes these distinct read like structures containing the genetic information that is passed from one generation of cells to the next.
What is the nucleolus?
A small dense region in the nucleus where the assembly of ribosomes begins.
On which organelle are proteins assembled?
Ribosomes.
What is the site where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell?
Endoplasmic reticulum
What is the difference between rough endoplasmic reticulum and smooth endoplasmic reticulum?
They are given these names because the rough ER contains ribosomes on its surface while the smooth endoplasmic reticulum doesn’t have ribosomes on its surface.
Which endoplasmic reticulum is involved in the synthesis of proteins?
Rough ER
In many cells what does the smooth ER contain?
It contains collections of enzymes that perform specialized tasks including the synthesis of membrane lipids and the detoxification of drugs
What is the function of the golgi apparatus
To modify sort and package proteins and other materials from the endoplasmic reticulum for storage in the cell or secretion outside the cell.
Which organelle breaks down lipids carbohydrates and proteins into small molecules that can be used by the rest of the cell?
Lysosomes.
What is the function of the vacuole.
It’s stores materials such as water salts proteins and carbs
In plant cells what is the function of the large central vacuole?
To support heavy structures such as leaves and flowers
Which unicellular protist contain the contractile back you’ll?
The Paramecium.
What are the two ways that most cells get energy?
From food molecules or from the sun
What is the function of the mitochondria
They convert the chemical energy stored in food into compounds that are more convenient for the cell to use. it is also the site of cellular respiration in multicellular organisms
What is the function of the chloroplast
They are organelles that capture the energy from sunlight and converted into chemical energy in a process called photosynthesis
Eukaryotic cells are given their shape and internal organization but is supporting structure called…?
The cytoskeleton.
What are the two principal protein filaments that make up the cytoskeleton?
Microtubules and microfilaments
Which part of the cytoskeleton is made up of proteins known as tubulin.
Microtubules
Which organelle is located near the nucleus and helps organize cell division
Centrioles
What is the thin, flexible barrier that surrounds all cells?
The cell membrane
What is the function of the cell wall?
A strong supporting layer around the membrane.
