Cell Structure Flashcards
What’s the difference between prokaryotic and eukaryotic cells?
Prokaryotic:
Smaller/ more simple cells
Lack membrane bound organelles
Has no nucleus
Reproduce asexually (Binary fission)
Eukaryotic:
Larger/ more complex cells
Membrane bound organelles present (including nucleus - house DNA)
Reproduce sexually (meiosis) and asexually (mitosis)
What’s an example of a prokaryotic and eukaryotic cell?
Prokaryotic:
Any bacteria, yeast, etc
Eukaryotic:
Animal/ plant cells, any specialized cells (brain cells, red blood cells, etc)
What does the nucleus do?
It directs all cell activities (tells the cell what to do)
It also holds DNA - which contain hereditary instructions for everything the cell does
What is the nuclear envelope and what does it do?
A double membrane that surrounds the nucleus. It contains pores.
It regulates the movement of substances into and out of the nucleus
It forms connections with the endoplasmic reticulum
Involved in protecting DNA and regulating the creation of RNA and proteins
What is the nucleolus and what does it do?
The “brain” of the nucleus
It’s located within the nucleus
It makes components of ribosomes (ribosomal RNA rRNA)
What is the endomembrane system and what does it do?
A group of organelles that interact between the nucleus and the plasma membrane
Function is to make biomolecules to be moved throughout the cell (eg. lipids, proteins, etc)
Also aids in recycling waste and destroying toxins
What is the endoplasmic reticulum and what does it do?
Network of tubes/ membranes that branch off the nuclear envelope
The endoplasmic reticulum carries materials throughout the cell
What are the two types of endoplasmic reticulums?
Rough - Ribosomes present on the surface
The site of protein synthesis (growing polypeptide chain)
Smooth - No ribosomes on the surface
Enzymes from rough endoplasmic reticulum help produce membrane lipids
What is a ribosome and what does it do?
A ribosome is a small body free/ attached to the endoplasmic reticulum
It’s function is to produce proteins (does so on the rough endoplasmic reticulum)
What are vesicles and what are their functions?
Vesicles are membrance enclosed organelles that branch off of the membrane of other organelles and move through the cell
Primary function is to transport materials throughout the cell (especially proteins)
Also helps breakdown larger macromolecules
What are vacuoles and what do they do?
Fluid filled sacs found in both plant and animal cells.
It stores water, food and waste
What are lysosomes and what do they do?
Small, round structures with a membrane
Digestion - breaking down large food molecules into smaller molecules
Protection - attacks foreign substances to break down
Usually work by fusing with vacuoles to breakdown the waste trapped inside
What are golgi bodies and what do they do?
Stack of membrane-bound vesicles
Package, moves and sorts substances to be transported around/ out of the cell
Adds final modifications (cofactors, carbohydrates, etc) to proteins and lipids delivered from endoplasmic reticulum before shipping to it’s final destination in/ out of the cell
What’s the mitochondria and what does it do?
Bean shaped with inner membranes containing it’s own DNA
Mitochondria is where ATP is made - requires oxygen
It breaks down sugar molecules into energy (cellular respiration)
What are plastids and what do they do?
Plastids are membrane enclosed organelles
Used for photosynthesis or storage
Chloroplasts, chromoplasts and amyloplasts are common types of plastids
What are chloroplasts and what do they do?
Green, oval structures that are only found in photosynthetic cells
It contains the green pigment chlorophyll as well as it’s own set of DNA
Organelle where energy from the sun is utilized to make food for the plant
What is the cytoplasm and what does it do?
Liquid/ gelatin-like inside of the cell that constantly flows/ moves
Used to hold organelles in place
What is the cytoskeleton and what does it do?
Scaffolding-like structure in cytoplasm
Helps cell maintain or change it’s shape
Can assist in movement
Made of structural proteins (rigid)
What are microtubules and what do they do?
Microtubules are long, hollow cylinders made of subunits of the protein tubulin
They form a dynamic scaffolding that can be built and broken down as needed
What are microfilaments and what do they do?
Fiber of the protein actin
Assist in strengthening or changing the shape of the cell
Responsible for muscle contraction
What are intermediate filaments and what do they do?
Most stable scaffolding - contains fibrous protein with globular heads and a tail
Helps maintain cell and tissue structures
What are the types of microtubules that assist with movement of the cell?
Cillia - Hair like projections that move water and mucus (often in epithelial tissue), assist in movement of prokaryotic cells
Flagella - Whiplike tail that is used for propulsion (propels cell forward)
Pseudopods - Internal microtubules which push out on the cell membrane to allow movement (known as false feet)
What is the plasma/ cell membrane and what does it do?
Outer covering/ protective layer around ALL cell types - primarily composed of phospholipids with proteins/ other lipid structures (eg. cholesterol)
For cells with cell walls, the cell membrane is inside the cell wall
Selectively permeable substance that controls the flow of materials into and out of the cell (Eg. allows oxygen, water and food to enter the cell and allows waste to exit the cell)
What is the cell wall and what does it do?
A rigid, protective layer in plant cells, algae, fungi and most bacteria - typically made of cellulose (chitin in fungi)
Protects the cell and gives it shape
What are the components of a membrane that surround the outside of the cell?
Extracellular matrix - secreted mixture of fibrous proteins and polysaccharides
The surounding and organzing component outside of the cell
Helps to organize cells based on type of secretions
Cell junctions - Structures that connect a cell to other cells allowing for an exchange of ions, nutrients or signaling between cells/ the environment
