2.1 cell structure and microscopes Flashcards

Question

use a named example to explain why staining is needed for light microscopes.

Answer 1

the main reason for staining is to highlight cells and parts of cells for a better visual, for example, acetic orcein stains DNA and chromosomes in cells dark red

Answer 2

put the slide on the STAGE and clip it in place turn on the power supply and light source look through the EYEPIECE and make sure the OBJECTIVE LENS is on the lowest magnification adjust your FINE and COARSE focus as well as IRIS DIAPHRAGM

Answer 3

mm -> microm =*1000 micromm-> mm=/1000 microm -> nm=*1000 nm ->microm /1000

Answer 4

magnification = image size/actual size

Answer 5

prokaryotic cells contain a cell wall and plasmids in the cytoplasm. However, it doesn't have a nucleus and membrane-bound organelles

Answer 6

they contain: a waxy protective capsule peptidoglycan cell wall plasma membrane mesosome plasmid pili ribosomes cytoplasm DNA loop flagella

Answer 7

the idea that eukaryotes arose from prokaryotes- that organelles were once prokaryotes ingested by a larger bacteria

Answer 8

the nucleolus is inside the nucleus

Answer 9

the nucleus is surrounded by a double membrane called the nuclear envelope that contains pores the outer membrane joins up to the endoplasmic reticulum it is the largest organelle 10-20micro metres in diameter the nucleoplasm contains chromatin

Answer 10

contains nearly of all a cells genetic material; instructions for making proteins and makes mRNA for protein synthesis

Answer 11

not surrounded by a membrane the dense spherical structure inside the nucleus

Answer 12

makes RNA and ribosomes that pass into the cytoplasm through the nuclear pores

Answer 13

non-membrane bound small spherical organelle that is about 20nm in diameter made of ribosomal RNA made in the nucleolus as two separate sub-units which pass through the nuclear envelope into the cytoplasm and then combine (40s and 60s sizes )

Answer 14

ribosomes that bind to the exterior of the endoplasmic reticulum are mainly used for synthesising proteins that will be exported outside the cell ribosomes that are free in the cytoplasm, either singly or in clusters are primarily the site of assembly of proteins that will be used inside the cell

Answer 15

system of membranes containing fluid-filled cavities (cisternae) that are continuous with the nuclear membranes coated in ribosomes

Answer 16

it is the intracellular transport system: the cisternae form channels for transporting systems from one area of a cell to another provides a large surface area for ribosomes which assemble amino acids into proteins - these proteins then actively pass through the membrane into the cisternae and are transported to the Golgi body for modification and packaging

Answer 17

system of membranes with fluid-filled cavities (cisternae)that are continuous with the nuclear membrane no ribosomes

Answer 18

contains enzymes that catalyse reactions involved with lipid metabolism such as: -synthesis of cholesterol - synthesis of steroid hormones it is involved with absorption synthesis and transportation of lipids (from the gut)

Answer 19

consists of stacks of membrane-bound flattened sacs secretary vesicles bring materials to and from the Golgi body

Answer 20

proteins are modified for example: -adding sugar molecules to make glycoproteins -adding lipid proteins to make lipoproteins -being folded into their 3D shape then proteins are packaged into vesicles that are then pinched off and : -stored in the cell or -moved into the plasma membrane, either to be incorporated into the plasma membrane or exported outside the cell

Answer 21

they may be spherical or rod-shaped or branched and are 2-5 micrometers long they are surrounded by two membranes with a fluid-filled space between them. The inner membrane is highly folded into cristae the inner part of the mitochondrion is a fluid-filled matrix

Answer 22

site of ATP during aerobic respiration self-replicating so mare can be made if the cell needs more energy they are abundant in cells where much metabolic activity occurs

Answer 23

these are large organelles that are 4-10 micrometers long they are surrounded by a double membrane or envelope the inner membrane is continuous with stacks of flattened membrane sacks called thylakoids which contain chloroplasts. Each stack of thylakoids is called a granum the fluid-filled matrix is called stroma

Answer 24

chloroplasts are the site of photosynthesis during the first stage of photosynthesis, when light energy is trapped by chlorophyll and used to make ATP occurs in the grana, water is also split to supply hydrogen ions

Answer 25

these are small bags formed from the Golgi apparatus and each is surrounded by a single membrane they contain powerful hydrolitic (digestive) enzymes

Answer 26

they keep powerful hydrolitic enzymes separate from the rest of the cells they engulf old organelles or foreign matter, digest them and return the digested components to the cell for reuse they are abundant in phagocytic cells such as white blood cells and neutrophills

Answer 27

separate contents of the cell from the outside permeable so it allows solutions to pass-through

Answer 28

a thin flexible layer of phospholipids

Answer 29

on the outside of the plasma membrane made from bundles of cellulose fibers

Answer 30

strong and prevents plant cell from bursting when turgid provides strength and support maintains the cells shape permeable and allows solutions to pass through

Answer 31

surrounded by a membrane called the tonoplast and contains fluid

Answer 32

filled with water and solutes and maintains cell stability because when full it pushes against the cell wall and makes the cell turgid

Answer 33

made from phospholipids

Answer 34

used for transportation

Answer 35

Free ribosomes are mainly concerned with assembling proteins to be used within the cell. Ribosomes on RER mainly assemble proteins that are exported out of the cell.

Answer 36

Motor proteins drag chloroplasts along cytoskeleton threads or ‘tracks’.

Answer 37

To prevent them from digesting/breaking down the cell components.

Answer 38

consists of two bundles of microtubules at right angles to each other the microtubules are made of tubulin protein subunits arranged to form a cylinder

Answer 39

before the cell divides the spindle, made of threads of tubulin, forms from the centrioles. Then chromosomes attach to the middle part of the spindle and motor proteins walk along the tubulin threads and pull the chromosomes apart involved in the formation of cilia and undulipodia

Answer 40

they are 7nm in diameter and made of subunits of the protein actin

Answer 41

they are within the cytoplasm and give support and mechanical strength to keep the cell's shape stable and allow cell movement

Answer 42

10nm in diameter made of a variety of proteins

Answer 43

they anchor the nucleus within the cytoplasm extend between cells in some tissues between special junctions enabling cell-cell communication and allowing cells to adhere to a basement membrane stabilising the tissue

Answer 44

18-30nm in diameter made of protein subunits called tubulin

Answer 45

also, provide shape and support to cells and help organelles/substances move through the cytoplasm they form the track along which motor proteins (kinesin) walk and drag organelles from one part of the cell to another they form the spindle before a cell divides and these spindle threads enable a chromosome to be moved within the cell

Answer 46

to waft mucus

Answer 47

phagocytes the can move so that they can engulf pathogens

Answer 48

lace a stage micrometer on the stage of the microscope. Line up one of the divisions on the eyepiece graticule with a fixed point on the stage micrometer. Count the number of divisions on the eyepiece graticule that correspond with a set measurement on the stage micrometer. Calculate the distance in micrometres of one division on the eyepiece graticule.