Components of a cell Flashcards
What is the cell wall and its function?
A rigid cell covering around the cell, inside is cross-linked polysaccharides and proteins Made of either: - Cellulose - Chitin - Peptidoglycan Functions: - Structure - Protection - Shape
What is the central vacuole and its function?
- Large plant organelle in the middle of the cell
Functions: - Regulates cells storage compartment,
- Holds water,
- The site for macromolecular degrading in cell growth
What is the centrosome?
A region in an animal cell made of two centrioles
What is the chloroplast and its function?
A Plant organelle that carries out photsynthesis
What are cilium and its function?
Plural for cilia, hair like structures that extend from the plasma membrane
Functions:
- Used to move entire cells or substances outside surface of the cell
What is cytoplasm and what is it comprised of?
The entire region between the plasma membrane and the nuclear envelope, Consists of: - Cytosol - Organelles - Cytoskeleton, - Various chemicals
What is the cytoskeleton and its function?
A network of proteins fibers made of microfilaments, microtubules, and intermediate filaments
Functions:
- Maintain the shape of the cell/structure
- Hold organelles in place/move organelles
- Allow the travel of vesicles in cells
- Enable unicellular organisms to move independently
- Anchors cells in place
What is a desmasome?
A link between to epithelial cells that keep tissues together,
- Allows water to pass between the junction
- Gives some space between connected cells, which is good for stressed cells
What is endoplasmic reticulum (ER) and its function?
The largest membranous structure (multiple interconnected membranes) in a eukaryotic cell,
- It buds of the nucleus
Function:
- Modify proteins and synthesize lipids
- Transport structures like proteins to the Golgi apparatus
What is the extracellular matrix?
Material that provides mechanical protection and anchoring tissues for other cells Such as: - Primary collagen, - Glycoproteins, - Proteoglycans
What is the flagellum and its function?
Long hair-like structures that extend from the plasma membrane
Function:
- Used to move the cell
What is a gap juntion?
A channel between two adjacent animal cells:
- Allows ions, nutrients, and low molecular weight substances to pass between cells
Function:
- Allows cells to communicate
(Kind of like a bridge between cells)
What is the Golgi apparatus and its function?
Eukaryotic organelle made of flattened stacked membranes
Function:
- Modifies proteins made in the RER
- Sorts, tags, and packages lipids and proteins for distribution
- Synthesizes molecules that need to be secreted from the cell
What is an intermediate filament and its function?
A Component of the cytoskeleton, and composed of several intertwined strands of fibrous protein
Function:
- resist tension,
- Supports cell-cell junctions
- Anchors cells to extracellular structures
What is a lysosome and its function?
An animal cell organelle found in the cytoplasm
Functions:
- digestive component of the cell
- digests proteins, lipids, polysaccharides (carbs), nucleic acid and aged organelles
What is a microfilament and its function?
Narrowest element of the cytoskeleton system
Function:
- Provides a rigid shape to the cell and enables cellular movement
What is a microtubule and its function?
Widest element of the cytoskeleton system
- Is also the structural element of centrioles, flagella and cilia
Function:
- Helps the cell resist compression
- Provides a path for vesicles to move along
- Acts as the spindelfibers in mitosis
What is mitochondria and its function?
Organelle responsible for cellular respiration,
- produces ATP for energy
What is a nucleoid?
Central part of a prokaryotic cell where the unique chromosome is found
What is the nucleolus and its function?
Darkly staining body in the nucleus,
Function:
- Assembles the subunits of the ribosomes from rRNA
What is the nucleus and its function?
An organelle that houses the cells DNA
Function:
- Holds genetic info
- Directs synthesis of ribosomes and proteins
What is peroxisome and its function?
A small, round organelle that contains hydrogen peroxide
Function:
- Oxidizes fatty acids and amino acids
- Detoxifies many poisons
What is the plasma membrane and its function?
A phospholipid bilayer with embedded proteins
Function:
- Seperates the internal content of the cell from external content
What is the plasmodesma and its function?
Channels between two adjacent plant cells, similar to a gap junction,
Function:
- Allows ions, nutrients, hormones, some RNA and proteins, and low weight substances to pass between cells
- Enables communication between cells
What is a ribosome and its function?
A cell structure that carries out protein synthesis made of rRNA and protein but not membrane bound
What is the rough endoplasmic reticulum (RER) and its function?
Region of ER where ribosomes are embedded
Function:
- Site of protein synthesis
What is the smooth endoplasmic reticulum (SER) and its function?
Region of ER that has very few ribosomes Function: - Synthesizes lipids (like steroids or phospholipids) - metabolizes carbs - Detoxifies drugs and toxins - Stores calcium ions
What is a tight junction and its function?
A firm seal between tow adjacent animal cells created by a protein adherence
- No water or ions can travel between cells connected like this
What is a vacuole and its function?
A membrane bound sac, like a larger vesicle
Function:
- Cellular storage and transport
What is a vesicle?
A small membrane bound sac
Function:
- Storage and transport
- capable of fusing with the plasma membrane and membranes of the ER and the Golgi apparatus
What is the difference between the protein formed the cytoplasm and the Rough endoplasmic reticulum?
- In the cytoplasm, the proteins may stay in the cytosol or go to other organelles,
- In the rough endoplasmic reticulum, the proteins are secreted from the cell
- integrated into the cell membrane
- Or become part of the ER, Golgi, or Lysosomes
What is the secretory pathway?
The pathway taken by a protein to get from the endoplasmic reticulum to the cell membrane or a lysosome
What are the organelles or strucutes included in the secretory pathway?
ER -> Golgi apparatus -> Lysosomes/Cell membrane
What are the unique components of a plant cell compared to an animal cell?
- Chloroplasts
- Cell wall
- Plasmodesmata
What organelle is the site for lipid synthisis?
Smooth Endoplasmic reticulum
What is an Erythrocyte?
A red blood cell
How are Erythrocytes specialized?
- Lack organelles so they can transport more blood,
- Biconcave disc shape so they have more surface area
What experiment can you do to test for the organelles in a cell?
Staining technique
What factors can affect structure/function?
- Shape
- Size
- Subcomponents/ abundance of organelles
What organelle is abundant in cells that specify in movement?
Mitochondria
What is it called when a cytoskeletal structure can change its length?
Dynamic instability
What side of the microtubule or microfilament does the change in length occur for dynamic instability?
The plus side
What structures do have dynamic instability?
Microtubules/filaments
What is the purpose of dynamic instability?
- Allows movement in a cell
- Spindle fibers in mitosis
- Maintains the shape of a cell
What are microtubules made of?
Dimers called tubulin
What are microfilaments made of?
Actin monomers
What are motor proteins?
Proteins that are involved in movements:
- Myosin
- Actin
Why are cells small?
To maintain a good SA:V,
- The volume of a cell determines its metabolic rate
- The Surface Area determines the amount of substance that can go to and from the cell
What happens to the metabolic rate compared to the surface area as a cell grows in size?
- The metabolic rate and need for resources grows faster than the surface area of the cell,
- Some large cells create folds to compensate for a lower SA
- As size increases, SA:V decreases = lower efficiency
How can cells overcome an issue in efficiency without getting smaller?
- Folding to increase SA
- Compartmentalize reactions (organelle)
- Change the shape of the cell
What does the volume of a cell allow us to predict?
How quickly substances diffuse into the cell
What does the surface area of a cell allow us to predict?
How much a cell interacts with the extracellular environment
What is compartmentalization?
Cells have organelles that have specific functions in order to increase efficiency in the cell
What is endomembrane system?
A series of infoldings from the plasma membrane that created organelles in a cell
What is included in the endomembrane system?
- Golgi
- Nucleus
- ER
- Vesicles
- Vacuoles
