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33 Cards in this Set
- Front
- Back
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What is the plasma/cell membrane?
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A double layer of phospholipids (lipid bilayer). The exposed heads of the bilayer are "hydrophilic (water loving),and the hidden tails of the phosopholipids are "hydrophobic" (water fearing). Proteins are also present including receptors for odors, tastes and hormones. The membrane allows molecules to pass in & out of the cell.
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What is the cytoskeleton?
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Maintains cell shape, helps organise cell division, functions as a system of roads for motor proteins.
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What are mitochondria?
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Known as the 'power houses' of the cell, they combine food (sugar) with oxygen to produce ATP - the primary energy source for the cell. Cells with more energy requirements have more mitochondria.
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What is the role of the nucleus?
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Acts as the 'Control Centre' of the cell, stores & protects DNA.
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Where is the nucleolus found & what does it do?
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Inside the nucleus, is the nucleolus. It produces ribosomes, which move out of the nucleus and take positions on the rough ER where they are critical in protein synthesis.
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What is the cytosol?
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Mainly water, this is the 'soup' where all the other organelles reside inside the cell.
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What is the cytoplasm?
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The cytosol & the organelles within it.
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What is the Golgi apparatus?
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The sorting & packaging plant likened to a stack of pancakes, where molecules are packaged for delivery to other parts of the cell, or for secretion from the cell.
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What are lysosomes?
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The 'stomachs' of the cell. They digest viruses & bacteria, excess or worn out organelles and food particles.
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What are vesicles?
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Membrane-bounded sacs that store & transport substances.
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What is the smooth endoplasmic reticulum resposible for?
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Synthesis of lipids.
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What is the rough endoplasmic reticulum resposible for?
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Proteins synthesized on the ribosomes collect in the endoplasmic reticulum for transport throughout the cell.
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What gives rough ER the 'rough' appearance?
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The ribosomes on its surface.
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What are ribosomes?
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Each ribosome comprises two parts, a large subunit and a small subunit. They are the site of protein synthesis.
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Where are ribosomes found?
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Throughout the cell, and on the rough endoplasmic reticulum.
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Name the 3 parts of the human cell.
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1. Plasma membrane
2. Cytoplasm 3. Nucleus |
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What is the function of chromatin?
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To package DNA into a smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and prevent DNA damage, and to control gene expression and DNA replication.
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How many chromosomes are in the human cell, and therefore how many DNA molecules?
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46 chromosomes (23 pairs), therefore 46 DNA molecules.
*One DNA molecule forms one chromosome. |
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Eukaryote cells generally reproduce themselves by which process?
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Mitosis.
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What are the 5 phases of mitosis?
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1.Interphase
2.Prophase 3.Metaphase 4.Anaphase 5.Telophase |
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What is interphase?
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The portion of the cell cycle when the cell is not going through mitosis.
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Where are lysosomes produced?
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The Golgi Apparatus.
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Describe the structure of DNA.
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The DNA molecule looks like a twisted ladder & is called a 'double helix.' The 'rungs' are built with the 4 letter DNA alphabet, A,C, T & G.
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How does the DNA's alphabet pieces (the 'ladder rungs') join together?
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A always pairs with T,
& C always pairs with G. |
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How does DNA replicate itself?
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The 2 strands of the double helix separate ('unzip') & the cell reads each strand, a base at a time and every time it sees a G, it sticks a C on the new complementary strand, an A for every T, a C for every G and a T for every A etc.
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DNA is made up of 2 strands that stick together to make a________________?
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Double helix.
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What is the nucleosome?
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The basic unit of DNA packaging. It consists of a segment of DNA wound in sequence around eight histone protein cores.(Like a thread wrapped around a spool).
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What happens during prophase?
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First stage of mitosis. Chromatin coils so the chromosomes are visible, nuclear membrane dissolves, centrioles migrate to opposite ends of cell, a spindle made of microtubules forms.
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What happens during metaphase?
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Chromosomes position themselves along the equator of the cell.
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What happens during anaphase?
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Sister chromatids separate and the two sets of chromosomes move toward opposite ends of the cell.
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What happens during telophase?
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Chromosomes begin to uncoil and a nuclear membrane forms around each set of chromosomes. Cell division.
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What is the plural of nucleolus?
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Nucleoli.
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What are the 6 functions of proteins in the plasma membrane?
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-Transport
-Enzymatic activity -Receptors -Intercellular joining -Cell-cell recognition -Attachment to cytoskeleton |
