Cell Structure: Key Words (Ms.D) Flashcards
What is a CARRIER PROTEIN?
-A PROTEIN on the CELL SURFACE
-That helps TRANSPORT MOLECULES and IONS across a PLASMA MEMBRANE
What is CENTRIFUGATION
-Process of SEPARATING CELLS of diff SIZE and DENSITIES
-By SPINNING them at HIGH SPEEDS in a CENTRIFUGE
What is a CHROMATID?
-1 of 2 COPIES of a CHROMO
-Joined together by 1 CENTROMERE PRIOR to CELL DIVISION
What is CHOLESTEROL?
A LIPID that is an important component of CELL-SURFACE MEMBRANES
What is a CHROMOSOME?
-THREAD-LIKE STRUCTURE made of PROTEIN & DNA
-Carries HEREDITARY INFO PHYSICALLY from 1 GEN to the NEXT
What is DIFFERENTIATION?
Process of CELLS becoming SPEACIALISED for DIFF FUNCTIONS
What is DIFFUSION?
-Movement of MOLECULES or IONS
-From a region of HIGH–>LOW CONC
What is a EUKARYOTIC CELL?
A CELL that has MEMBRANE-BOUND NUCLEUS & CHROMOS
What is FACILITATED DIFFUSION?
-Diffusion involving PROTEIN CARRIER molecules
-To allow PASSIVE MOVEMENT of SUBSTANCES across PLASMA MEMBRANES
What is a GLYCOPROTEIN?
Substance made up of a PROTEIN molecule and a CARBOHYDRTAE molecule
What is GRANUM?
-Stack of THYKALOIDS in CHLOROPLASTS that resembles a pile of coins
-Site of the LIGHT-DEPENDANT reaction PHOTOSYNTHESIS
What is a GUARD CELL?
-1 PAIR of CELLS surrounding a STOMA in PLANT LEAVES
-CONTROLS OPENINGS and CLOSINGS
What is a HIGH DENSITY LIPID (HDL)?
-A COMPOUND of PROTEIN & LIPID MOLECULES found in BLOOD PLASMA
-TRANSPORTS CHOLESTEROL from other CELLS–>LIVER
What is an INTRINSIC PROTEIN?
-PROTEIN of CELL-SURFACE MEMBRANE
-SPAN the PHOSPHOLIPID BILAYER from 1 side to another
What is an ION CHANNEL?
-PASSAGE across CELL-SURFACE MEMBRANE made up of PROTEIN
-OPENS & CLOSES to allow IONS to pass IN & OUT of CELL
What is meant by the term ISOTONIC?
SOLUTIONS that possess SAME CONC. of SOLUTES and SAME WATER POTENTIAL as its comparison
What is meant by the term IN VITRO?
Experiments performed outside of a living body
What is meant by the term IN VIVO?
Experiments performed inside a living body
What is a LOW-DENSITY LIPOPROTEIN?
-COMPOUND comprised of PROTEIN & LIPID MOLECULES that occurs in BLOOD PLASMA and LYMPH
-Carries CHOLESTEROL from LIVER–>other CELLS in BODY
What is a MESOPHYLL?
-Tissue between 2 layers of EPIDERMIS in a PLANT CELL
-Comprised off PALISADE CELLS and a lower layer of SPONGEY CELLS
What is the MIDDLE LAMELLA?
-Layer made of PECTINS and OTHER SUBSTANCES
-Found between WALLS of ADJACENT PLANT CELLS
What are PALLISADE CELLS?
-LONG, NARROW cells packed with CHLOROPLASTS
-Found in the UPPER region of a LEAF & carry out PHOTOSYNTHESIS
What is PHAGOCYTOSIS?
-MECHANISM by which a CELL ENGULFS PARTICLES
-To form VESICLES or VACUOLES
What is the PHLOEM?
-PLANT TISSUE that TRANSPORTS products of PHOTOSYNTHESIS
-From LEAVES to rest of the PLANT
What is a PHOSPHOLIPID?
TRIGLYCERIDES in which 1 of 3 FATTY ACID molecules is REPLACED by a PHOSPHATE molecule
What is a PLASMID?
Small CIRCULAR piece of DNA found in BACTERIAL CELLS
What is a PROKARYOTIC CELL?
A CELL that DOES NOT have a NUCLEUS or MEMBRANE-BOUND ORGANELLES
What is a PROTOPLAST?
-The LIVING PORTION of a PLANT CELL
-I.E, The NUCLEUS and CYTOPLASM along with the ORGANELLES it contains
What is a RECEPTOR?
A CELL ADAPTED to DETECT CHANGES in the environment
What is the RECOGNITION SITE?
A NUCLEOTIDE sequence that is RECOGNISED by a RESTRICTION NUCLEASE which ATTACHES to it
What is a SODIUM-POTASSIUM PUMP?
-PROTEIN CHANNELS across CELL-SURFACE MEMBRANES
-That use ATP to MOVE SODIUM IONS OUT of the CELL
-In EXCHANGE for POTASSIUM IONS that move IN
What is a STEM CELL?
UNDIFFERENTIATED DIVIDING CELLS that occur in EMBRYOS and in ADULT ANIMAL TISSUES that require CONSTANT replacement
What is the STOMA?
-A PORE, mostly in the LOWER EPIDERMIS of a LEAF
-Which GASES DIFFUSE IN & OUT of the LEAF
What is the STROMA?
-MATRIX of CHLOROPLASTS
-Where PHOTOSYNTHESIS takes place
What is SUPERNATENT LIQUID?
-LIQUID portion of MIXTURE left at the top of the tube
-When SUSPENDED PARTICLES have been SEPARATED out at BOTTOM during CENTRIFUGATION
What are the THYKALOID?
-SERIES of FLATTENED MEMBRANOUS SACS in a CHLOROPLAST
-That contain CHLOROPHYLL and associated molecules needed for PHOTOSYNTHESIS
What is a TISSUE?
-A group of SIMILAR CELLS
-Organised into a STRUCTURAL UNIT that serves a PARTICULAR FUNCTION
What is a TRIGLYCERIDE?
Individual LIPID molecule made up of a GLYCEROL molecule and 3 FATTY ACIDS
What is ULTRAFILTRATION?
Filtration assisted by BLOOD PRESSURE
What are VOLTAGE-GATED CHANNELS?
-PROTEIN CHANNELS across a CELL-SURFACE MEMBRANE
-That OPENS & CLOSES according to changes in ELECTRICAL POTENTIAL across the membrane
What is a XEROPHYTE?
A PLANT adapted to living conditions in DRY CONDITIONS
What are XYLEM VESSELS?
-DEAD, HOLLOW ELONGATED TUBES with LIGNIFIED WALLS and NO END WALLS
-That TRANSPORT WATER in MOST PLATNS
