cells + tissues

Vesicular transport is the movement of substances across the cell membrane in membranous sacs called vesicles. This is an active process, because energy from the cell is needed to form the vesicles.

Endocytosis is taking liquid or solids into the cell by vesicular transport. The cell membrane folds around a droplet of liquid or a solid particle until the droplet or particle is completely enclosed. The vesicle formed then pinches off and is suspended in the cell’s cytoplasm.

Taking liquids into the cell in this way is called pinocytosis; when the vesicles contain solid particles it is called phagocytosis.

<p>Exocytosis is 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.</p> Signup and view all the answers

<p>luidity: Phospholipids and other molecules move freely within the bilayer, keeping the membrane flexible.</p> <p>Phospholipid Bilayer: The membrane is composed of two layers of phospholipids, with hydrophilic heads facing outward and hydrophobic tails facing inward.</p> <p>Cholesterol: Embedded cholesterol molecules maintain membrane stability and prevent phospholipids from packing too closely.</p> <p>Mosaic Composition: The membrane contains various molecules, including proteins, cholesterol, and phospholipids, creating a &quot;mosaic&quot; pattern.</p> <p>Proteins in the Membrane: Proteins like receptors, channels, and carriers are distributed across or attached to the membrane, supporting various functions.</p> <p>Selective Permeability: The dynamic arrangement controls what substances enter and exit the cell, maintaining internal balance.</p> Signup and view all the answers

<p>acts as physical barrier -separates cytoplasm from extracellular fluid around cell</p> <p>regulates passage of materials -controls movement of materials into and out of the cell e.g. entry of ions and nutrients, removal of wastes</p> <p>sensitive to changes -first part of cell affected by any changes in extracellular fluid -has receptors that are sensitive to particular molecules in its surrounding env</p> <p>helps support the cell -internal part of cell membrane attached to microfilaments of cell's cytoskeleton, thus giving support to whole cell -also connections btwn membranes of adjacent cells, providing support to whole tissue</p> Signup and view all the answers

<p>passive or active -involves carrier proteins in cell membrane that bind and transport specialised molecules across membrane e.g. potassium and sodium ions against or along with concentration gradient</p> Signup and view all the answers

<p>the movement of water molecules across a SEMI-PERMEABLE membrane from LOW SOLUTE CONCENTRATION to HIGH SOLUTE CONCENTRATION until equilibrium reached.</p> Signup and view all the answers

<p>tightly packed cells = smooth surface line inside of alimentary canal and outside of lungs and liver **covering/lining tissue</p> Signup and view all the answers

<p>provide support for body and hold all body parts together -cells are not close together, separated from each other by large amounts matrix</p> <p>e.g. bone, cartilage, blood</p> Signup and view all the answers

<p>three types: skeletal: muscle attached to bones voluntary striated</p> <p>smooth: non-striated walls of stomach and intestines, BV involuntary contractions</p> <p>cardiac: myogenic heart muscle involuntary</p> Signup and view all the answers

<p>control all cellular activities store genetic information produce ribosomes</p> Signup and view all the answers

<p>HAS digestive enzymes to break down materials, cellular waste and damaged digestive enzymes digest harmful bacteria and viruses</p> Signup and view all the answers

<p>lipid synthesis detoxification of drugs store calcium ions</p> Signup and view all the answers

<p>has ribosomes, synthesis/transport proteins</p> Signup and view all the answers