Cells Flashcards
Name the two types of cells
Prokaryotic and Eukaryotic
What are Prokaryotic cells?
singled-celled organisms with a simple structure of just a single undivided internal area called a cytoplasm (composed of Cytosol)
What are Eukaryotic cells?
Eukaryotic cells have a membrane bound nucleus and cytoplasm which contains many membrane-bound components.
What do Metabolic reactions consist of?
Synthesis reactions and breaking down reactions.
What do membranes do?
membranes are selectively permeable and control the movement of substances into and out of the cell and organelles. Membranes are effective barriers in controlling which substances enter and exit the cell but they are fragile.
What does the nucleus contain
coded genetic info in the form of DNA.
What does DNA do
directs the synthesis pf all proteins required by the cell (protein synthesis)
Controls all metabolic activities.
What is the double membrane called that contains the DNA and what is its function?
The nuclear envelope and its function is to protect the DNA from damage in the cytoplasm.
What do the nuclear pores do?
Allow molecule to move into and out of the nucleus.
What protein does DNA associate with and what does it do?
DNA associates with Histones, which causes it to form a complex called Chromatin. Chromatin coils and condenses to form structures known as chromosomes.
What is the nucleolus?
The nucleolus is an area within the nucleus and is responsible for producing ribosomes.
What makes up the nucleolus?
Proteins and RNA
What does the RNA in the nucleolus form?
ribosomal RNA (rRNA) which is then combined with proteins to form ribosomes
What are the mitochondria?
The mitochondria are membrane-bund organelles. They are the site of the final stages of cellular respiration, and release the energy stored in the bonds of organic molecules.
What can the number of mitochondria in a cell show?
How active the cell is, by resembling how much it needs to respire.
What is the structure of a mitochondria?
Mitochondria hace a double membrane. The inner membrane is highly folded to form structures called cristae , and the fluid interior is called the matrix. The membrane forming the cristae contains the enzymes used in respiration.
What are vesicles and what are their functions?
Vesicles are membrane bound sacs, that transport materials inside the cell. They consist of a sign membrane with a fluid inside.
What are lysosomes and what ate their functions?
Lysosomes are specialised forms of vesicles that contain hydrolytic enzymes. They are responsible for breaking down waste material in cells.
What is the cytoskeleton?
The network of fibres necessary for the shape and stability of the cell. It holds organelles in place and controls cell movement and the movement of organelles in the cell.
What makes up the cytoskeleton?
Microfilaments, microtubules, Intermediate fibres
What are microfilaments?
Microfilaments are a part of a cells cytoskeleton, they are formed by the protein actin. They are responsible for cell movement and cell contraction during cytokinesis.
What are microtubules?
Microtubules are a part of a cells cytoskeleton, they are globular tubular proteins polymerised to form tubes that form tubes. They determine the shape of the cell, and also act like tracks for the substances moving around the cells, eg vesicles.
What are the intermediate fibers?
Intermediate fibres are apart of the cytoskeleton, they give strength to the cells and maintains the integrity of the cells.
What are chloroplast and what is their structure and function?
Chloroplasts are responsible for Photosynthesis. Chloroplasts contain two fluid separated membranes and the inner membrane is folded into a network of flattened sacs called Thylakoids that are stacked into Grana (one Granum, two Grana). The Thylakoids contain Chlorophyll in which the process of Photosynthesis occurs.