Cell Structures and Functions Flashcards
“Principal’s Office”
Houses DNA
chromatin phase-loose DNA
chromosome phase-tightly packed DNA
Nucleus
Has Pores, protects nucleus, Double Membrane (phospholipids) (one side is hydrophilic and one side is hydrophobic)
Nuclear membrane
“Photocopier”
Makes copies of DNA
Nucleolus
Holds cell together, Keeps organelles in place
Cytoplasm
Protects and supports cell
cell membrane
Not organelles, Make proteins
Ribosomes
2 types of ribosomes
Free and bound
Make proteins that stay within the cell
Free ribosomes
Make proteins that will leave the cell
Bound ribosomes
The endoplasmic reticulum is composed of small tubes called _________
cisternae
Helps with the synthesis of lipids, phospholipids, and steroids, Helps break down carbohydrates (ex. Glycogen ((stored sugar)) to Glucose), Helps to detoxify blood (Liver cells = Lots of ____)
Smooth Endoplasmic Reticulum (SER)
Helps with protein synthesis (provides a H2O free environment for protein folding), Ribosomes are bound to the outside and deposit proteins inside as it is made by the ribosome
Rough Endoplasmic Reticulum
Modifies proteins by attaching sugars (called Glycoproteins)
(It’s like a gift wrapping to disguise the protein for export through the cell membrane), composed of flattened tubes called cisternae
Golgi Apparatus
Act like the “stomach” of the cell, Involved in digestion and recycling (autophagy), Full of digestive enzymes (lysozomes), Composed of phospholipid bilayer
Lysosomes
Act as “closets” for storage of materials
Various types exist (food, contractile, central)
Vacuoles and Vesicles
The process of bringing something into the cell
Endocytosis
Process of cell “eating”
Phagocytosis
The process of cell “drinking”
Pinocytosis
Involved in making energy by the performing the process of cellular respiration, Has its own DNA, Has cristae (folded inner membrane) that increases surface area for making energy, _________ matrix has ribosomes and is the site for the Kreb’s Cycle of Cellular Respiration, Evolutionarily significant
Mitochondria
Site of photosynthesis in plants and algae, They are a type of plastid (any of a class of small organelles containing pigment or food.), Has its own DNA ribosomes and enzymes (ATP synthase)
Chlorophyll
Site of light reaction of photosynthesis (ATP from reaction will be used as energy for making sugar in Calvin Cycle)
Thylakoid
Stack of thylakoids
Grana
Watery space between thylakoids and outer membrane (site of Calvin Cycle of Photosynthesis)
Stroma
Proposed that prokaryotes came to live in a symbiotic relationship (the smaller living inside the larger), Eventually these prokaryotes evolved into eukaryotic cells over hundreds of thousands of years
Endosymbiont Hypothesis
Benefits of a smaller cell living inside a larger
Larger gains energy
Smaller gains protection
Helps support and protect the cell, Keeps inner organelles organized, Helps with motility, Composed of various sized protein fibers, Composed of microtubules
Cytoskeleton
What is motility?
cell movement
Large hollow tubes, Composed of tubulin protein, Main function is for support and movement, Help guide movement for organelles
Microtubules
Anchor during cell division, made of microtubules
Centrosomes/centrioles
“Tow ropes”, Used to move chromosomes during mitosis or meiosis, made of microtubules
Spindle fibers
Help with cell movement through wavelike movements
Cilia
Help with cell movement, Fewer than cilia and longer in length, Undulating (whipping) movement
Flagella
Smallest structures in the cytoskeleton, Solid rods, Composed of actin or myosin protein, Provide a “pulling force”, Abundant in muscle tissue
Microfilaments
For protection and durability (holding up plant structure)
Cell wall
Primary cell wall composition
cellulose sugar
Middle lamella composition
Pectin sugar (“Super glue” between cell walls that hold them together)
Secondary cell wall composition
cellulose sugar
Outer protective “skeleton” of the cell plasma membrane in animal cells
Also functions in communication with other cells (use glycoproteins to communicate)
Composed mostly of glycoproteins and glycolipids
Extracellular matrix
Help to hold cells together so they may work together
Some are tunnels for cell to cell communication
Cellular Junctions
Composed of cells
Responds/adapts to environment
Uses energy
Grows and reproduces
Characteristics of a living thing
Said to be selectively permeable, Phospholipids make up the majority of it
cell membrane
Meaning of cell membrane being selectively permeable
Selects what materials enter or exit the cell through the membrane
Membrane also helps to regulate control of homeostasis (stable internal environment) by controlling entry and exit of certain molecules
These molecules are said to be amphipathic (have a hydrophobic and hydrophilic region)
Phospholipid
These molecules created bi-layer and the structure is held intact by the presence of water inside and outside the cell
Phospholipid
Remember proteins fold into 3D structures and that proteins are composed of amino acids that have water _______ and water ________ regions)
loving, fearing
Two types of membrane proteins
integral, peripheral
Types of membrane protein, Run completely through the bi-layer from outside to the inside, These function in the transport of molecules and for stability (help maintain integrity of the structure)
Integral
Type of membrane protein, Located on 1 side of the membrane (do not extend into the bi-layer of the membrane), Act as sites for attachment of the cytoskeleton
peripheral
Functions of membrane proteins?
Transport (Move food, water, etc across membrane), Act as enzymes (control metabolic processes), Cell to cell communication and recognition (so cells can work together in tissues), Intercellular junctions (for “stitching” together to make tissues), Attachment points to the cytoskeleton and extracellular matrix
This molecule helps keep the membrane of all cells flexible
Cholesterol