Cells Flashcards

Question

What molecules are embedded in the phospholipid bilayer of the cellular membrane, and what are the important for?

Answer 1

-Chloresterol and protein molecules, recepor proteins, channel proteins, carrier proteins and cell-identity markers -Important for the function integrity and stability of the membrane

Answer 2

1. Acts as a physical barrier (separates the cell cytoplasm from the extracellular fluid around the cell) 2. Regulates the passage of materials (controls the movement of materials into and out of the cell) 3. Is sensitive to changes (first part of the cell to be affected by any changes in the extracellular fluid) 4. Supports the cell (internal part of cell membrane is attached to the microfilaments of the cell's cytoskeleton, giving support for the whole cell. Also are connections between membranes of adjacent cells providing support to the whole tissue)

Answer 3

Cells are differentially permeable, semipermeable or selectively permeable allowing only certain ions/molecules to pass through but restrict the movement of others

Answer 4

-Diffusion (passive process) -Facilitated transport (passive or active transport) -Vesicular transport (active process)

Answer 5

-A passive process resulting from the random movement of ions and molecules -The spreading out of particles so that they are evenly distributed over the space available (occurs in gases + lquids because the molecules are constantly moving) -The difference in concentration that brings about diffusion is called a concentration gradient, or diffusion gradient (the greater the difference in concentrations, the 'steeper' the diffusion gradient and the faster the rate of diffusion)

Answer 6

The process of substances moving along the concentration gradient in a solution or across a semipermeable membrane, without the use of membrane proteins

Answer 7

-The diffusion of solvent (water) through a differentially permeable membrane in order to balance the concentration of another substance -Water will move from an area where a solute such as sugar is in low concentration to an area where the solute is in high concentration (low concentration to high concentration)

Answer 8

-Proteins in the cell membrane allow molecules to be transported across the mebrane (these proteins are channel proteins, which form protein channels, and carrier proteins, which allow carrier-mediated transport) -To diffuse across a cell membrane, water-soluble molecules must pass through portein channels in the membrane -Channel proteins are only open at one side at one time, so a substance binds at the binding site, and the protein will then change shape to open at the other side, releasing the substance -Two main types: Facilitated Diffusion and Active Transport

Answer 9

-Occcurs when substances are transported through a protein along the concentration gradient from a high concentration to low -Passive process (no energy input required)

Answer 10

-Requires energy in the form of ATp -Substances are transported across membrane against the concentration gradient (low to high) -Via carrier protens

Answer 11

-Movement of substances across the cell membrane in membranous sacs (vesicles) -Active process (energy is needed to form vesicles)

Answer 12

-Taking liquid or solids into the cell by vesicular transport -Cell membrane folds around a droplet of liquid or solid particle until the particle is completely enclosed -Vesicle is then pinched off at the end and suspended in the cell's cytoplasm

Answer 13

-When the contents of a vesicle inside the cell are passed to the outside -A vesicle that is formed inside the cell migrates to the cell membrane and fuses with the membrane -The contents of the vesicle are then pushed out into the extracellular fluid

Answer 14

-Larger surface-area-to-volume ratio than a larger cell -As cells grow, its ability to exchange enough materials to support its increasing volume is dimished because the volume is increasing at a greater rate than the surface area -Large cell could not support itself (not enough surface area to absorb nutrients required/remove wastes produced)

Answer 15

1. Cells (lowest structural level, specialised to carrt out different functions, e.g. muscle cells and red blood cells) 2. Tissues (cells with similar specialisations work together to carry out common functions, e.g. muscle cells make up muscle tissue) 3. Organs (made up of two or more tissues, e.g. stomach - made up of epithelial tissue on the inside and muscular tiisue in the wall) 4. System (a large group of organs that work together for a common purpose, e.g. respiratory system)

Answer 16

-Unicellar (only one cell) -Multicellular (many cells)

Answer 17

-Perform different jobs -Cell structure is altered and they contain different organelles depedning on what they do e.g. nerve cells, blood cells, muscle cells, bone cells etc.

Answer 18

Word: Glucose + Oxygen -> Water + Carbon Dioxide + Energy Equation: C6H12O6 -> 6H2O + 2CO2 + Energy

Answer 19

A pair of cylindrical structures usually located near the nucleus; involved in the reproduction of the cell

Answer 20

It is the ratio of a cell's outer surface area to its internal volume. A higher SA:V ratio increases the efficiency of exchange of materials (like oxygen and nutrients), which is why cells must stay small

Answer 21

Gives the cell shape and support Anchors organelles in place Aids in cell movement and movement of materials

Cells Flashcards

(45 cards)