2 Cells- Cell structure (eukaryotic) Flashcards
What is the structure of the cell-surface (plasma) membrane?
-Made from a phospholipid bilayer
-Have proteins- can act as receptors (cell can respond to external environment), and cholesterol embedded in them
What are the functions of the plasma membrane?
-Separates the inside of the cell from its environment
-Controls the passage of organic molecules, ions, water, and oxygen into and out of the cell
-Waste products (e.g. ammonia, CO2) leave the cell by passing through here
What is the structure of the cytoplasm?
-Organelles suspended in the gel-like cytosol
-70% water
-Contains proteins, sugars, ions and fatty acids
What are the functions of the cytoplasm?
-Many metabolic reactions take place here
-Different organelles perform specific functions here
What is the structure of the nucleus?
-Nucleoplasm (semi-solid fluid inside)
-Chromatin and nucleolus (1 or more) in nucleoplasm
-Linear chromosomes (eukaryotes), made up of DNA
-Nuclear envelope
What is the function of the nucleus?
-Controls the actions of the cell
-DNA in here has instructions for the synthesis of proteins
-Ribosomal RNA joins with associated proteins in nucleolus to assemble ribosomal subunits
What is the structure of the nuclear envelope?
-Double-membrane
-Pores
-Inner and outer membrane are phospholipid bilayers
What is the function of the nuclear envelope?
-Pores control passage of ions, molecules and RNA between nucleoplasm and cytoplasm
What is the structure of mitochondria?
-Oval-shaped, double-membrane (phospholipid bilayer, with proteins embedded)
-Have ribosomes and DNA
-Inner layer has folds, cristae
-Area surrounding folds= mitochondrial matrix (has enzymes for respiration)
What is the function of mitochondria?
-Make ATP via aerobic respiration (muscle cells have lots as they are highly active and need a lot of energy)
What is the structure of chloroplasts?
-Have DNA, ribosomes and inner and outer membranes
-Thylakoids= set of interconnected and stacked fluid-filled membrane sacs in the space enclosed by the inner membrane
-Each stack of thylakoids= granum (grana pl.), linked by lamellae, flat, thin parts of thylakoid membranes
-Stroma= fluid enclosed by inner membrane, surrounds grana
What is the function of chloroplasts?
Photosynthesis in plant and algal cells
What is the structure of the Golgi vesicles?
-Membrane-bound, fluid-filled vesicles in the cytoplasm
-Small, round, seen in high density near edges of sacs
-e.g. lysosomes
What is the function of the Golgi apparatus?
Transport vesicles form at endoplasmic reticulum, fuse with golgi apparatus;
these empty proteins and lipids into lumen of golgi apparatus, which travel through the golgi and are sorted, packaged and tagged so they can be sent to the right place
Form lysosomes
What is the structure of the Golgi apparatus?
Series of flattened membranous sacs
