Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
166 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What are specialised cells? |
Cells in multicellular organisms can specify in function |
|
|
|
Cellular organelles: |
h |
|
|
|
The Cell Theory |
1. All organisms are composed of cells (and the products of cells) 2. All cells come from pre-existing cells 3. The cell is the smallest living organisational unit. |
|
|
|
Cell wall |
Cellulose wall outside the plasma membrane of plant cells. |
|
|
|
Flagella |
Whip-like processes that are cell extensions, used for movement |
|
|
|
Cilia |
Cell extension. Small hair-like structures used for movement. |
|
|
|
Plasma membrane |
Also called cell membrane. All cells have an outer plasma membrane. Separates cell contents from the environment. Supports, prevents expansion, recognition, adhesion, chemical communication, allows water and dissolved substances to pass freely through it. Delicate bilayer (phospholipid) |
|
|
|
Cytoplasm |
Jelly-like. More than 90% water. Contains ions, slats, enzymes, food molecules, the nucleus and organelles. Everything other than nucleus. Where all metabolic reactions occur. |
|
|
|
Cytosol |
Fluid component of of the cytoplasm |
|
|
|
DNA |
All cells contain DNA, which carries hereditary information, directs the cell's activities and is passed accurately from generation to generation. |
|
|
|
Prokaryotes |
An organism with cells that do not have a membrane surrounding the nucleus and lack most organelles. All prokaryotes are bacteria and cynobacteria. Unicellular. |
|
|
|
Eukaryote |
An organism with cells in which the nucleus is surrounded by a membrane. Larger and more complex than prokaryotes. |
|
|
|
Chloroplast |
Green organelle (due to presence of chlorophyll) in which photosynthesis takes place. Composed of many folded layers of membrane. |
|
|
|
Endoplasmic reticulum |
A network of intracellular membranes that links with the plasma membrane and other membranous organelles. Rough ER is associated with ribosomes - transport of proteins. Smooth ER lacks ribosomes - transport of lipids. Involves the production, processing, transport and storage of materials in the cell. |
|
|
|
Golgi Apparatus |
A stack of flat membrane sacks where the final synthesis and packaging of proteins into membrane-bound vesicles occurs before they are secreted from the cell. Linked to ER. Packages substances for secretion. |
|
|
|
Centriole |
Involved in cell division. |
|
|
|
Cytoskeleton |
Structure for 3D shape |
|
|
|
Lysosome |
Membrane-bound vesicles containing powerful enzymes that break down debris and foreign material; suicide sac. |
|
|
|
Mitochondria |
Organelles composed of many folded layers of membrane. Mitochondria are involved in the energy transformations that release energy for use by the cell. Breaks down glucose to make ATP. |
|
|
|
Nucleus |
Double-layered nuclear membrane, containing pores that communicate with the cytoplasm. Contains DNA and controls cellular activities. |
|
|
|
Plastids |
Only found in plant cells. Develop organelles called proplasts e.g. chloroplasts, amyloplasts (store starch) etc. |
|
|
|
Ribosomes |
Tiny organelle. Site of production of proteins. |
|
|
|
Vacuole |
Membrane-bound, liquid-filled space. Provide storage and physical support through turgidity for plant cells. Can be involved in intracellular digestion (food vacuoles) or water balance (contractile vacuoles). |
|
|
|
Vesicles |
Membrane-bound organelles often associated with transport in a cell. |
|
|
|
Viruses |
Not classified as living organisms. Composed of genetic material and enclosed in a protein coat (capsid). |
|
|
|
What is pH? |
The measure of acidity or alkalinity (scale of 1-14) |
|
|
|
What is necessary in all cells? |
Nutrition, Growth, Reproduction, Response, Metabolism, Homeostasis |
|
|
|
What are enzymes? |
Enzymes are catalysts that speed up reactions in cells, making production faster - necessary because it would be too slow naturally. They are proteins. |
|
|
|
Is water organic or inorganic? What are some key properties? |
- Most organisms usually 70-90% water 80% cell = water Chemical reactions that take place in a cell take place in a watery medium - pH important for correct function enzymes - - Water molecules very cohesive which allows it to be pulled up trees without breaking - Surface tension -High heat capacity so when exercising water can absorb the heat. - Evaporation also effective in cooling body surface. |
|
|
|
Photosynthesis formula |
6CO2 + 12H20--> C6H12O6 + 6H20 + 602 |
|
|
|
Nitrogen - importance |
Nitrogen is the key component in proteins so it is required in relatively large amounts by organisms. Nitrogen fixation is when atmospheric nitrogen is trapped by certain bacteria and converted into compounds that can be used by plants (legumes, casuarinas, acacias |
|
|
|
Minerals |
- Phosphorus, potassium, calcium, magnesium, iron, sodium, iodine, sulphur are all biologically important minerals. -Many other minerals are needed in small (trace) amounts -Mineral salts are produced by the weathering of rocks and absorbed, as ions, into the roots of plants. -Mineral ions are found in the cytosol, bones, and in the molecules or enzymes and vitamins. |
|
|
|
Monosaccharide |
Monosaccharides are used as the main energy source for fuelling cell metabolism. Glucose, fructose, galactose |
|
|
|
Disaccharide |
Disaccharides are used as energy sources and as building blocks for larger molecules. They contain two linked monosaccharides. Maltose, lactose, sucrose |
|
|
|
Polysaccharide |
Polysaccharides are long chains ofdisaccharides that are joined together by glycosidic bonds. Cellulose, chitin, glycogen, starch. |
|
|
|
Cellulose |
STRUCTUAL COMPONENT of cell wall, xylem vessel components and wood.(PLANT) |
|
|
|
Chitin |
The STRUCTUAL COMPONENT occurring infungi and the exoskeleton of anthropods. (ANIMAL) |
|
|
|
Starch |
STORAGE MOLECULE (starch granules) ofplants. Broken down by enzyme amylase into the disaccharide maltose. |
|
|
|
Glycogen |
STORAGE COMPOUND in animal tissue,found in the cells of the liver and muscle. |
|
|
|
Glycosidic bond |
Those that join a sugar molecule covalently to another group that may or may not be another sugar. |
|
|
|
Hydrolysis reaction: |
Molecule of water is added to a substance which causes both substances and the water molecule to split into two parts. RELEASES ENERGY |
|
|
|
Condensation reaction |
Chemical reaction where two molecules combine to form a largermolecule, together with the loss of a small molecule (e.g. water). USES ENERGY |
|
|
|
Lipids |
Lipids are 'fatty' substances, including fats and oils Non-polar, hydrophobic. Source of fatty acids, important as hormones (sex hormones). Important energy-storing molecule. ORGANIC |
|
|
|
Carbohydrates |
Most abundant ORGANIC molecule in nature. |
|
|
|
Phospholipids |
Important component of cell membranes Composed of carbon, oxygen and hydrogen but in different proportions to carbohydrates. Much less oxygen, can contain other elements such as phosphorus and nitrogen. |
|
|
|
Most phospholipids consist of a glycerol attached to two fatty acids and a phosphate group. Phosphate end hydrophilic. Fatty acid hydrophobic. |
|
|
|
How are lipids broken down? |
Lipids are emulsified by bile in the small intestine and then are broken down by enzymes called proteases. |
|
|
|
Structure consists of a glycerol attached to one (mono), two (di) or three (tri) fatty acids. They provide twice as much energy as the same quantity of carbohydrate. |
|
|
|
Proteins |
Each kind of organism has its own unique proteins (unlike the similarity in lipids and carbohydrates) |
|
|
|
Some proteins act as: |
-the structural component of cells -enzymes -hormones -Other carrier molecules (haemoglobin that carries oxygen in blood) |
|
|
|
What are proteins made of? |
ALL Proteins contain carbon, hydrogen, oxygen and nitrogen. Can also contain sulphur, phosphorus and other elements. Proteins are composed of chains of smaller subunits called amino acids. |
|
|
|
How are amino acids linked? How many amino acids are commonly found in proteins? |
Amino acids are linked by peptide bonds, and proteins are called polypeptides or polypeptide chains. 20 different types of amino acids commonly found in proteins. |
|
|
|
Nucleic Acids |
Are the genetic material of all organisms and determine features of organism. |
|
|
|
What are the two types of nucleic acids and what are they composed of? |
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)BOTH are made of long chains of subunits called nucleotides. |
|
|
|
RNA |
RNA plays a major role manufacturing proteins within cells. |
|
|
|
Three components of nucleotides |
Nucleotides have three components: - a base - a sugar - a phosphate |
|
|
|
Structure. |
|
|
|
Vitamins |
Organic molecules required by animals in small amounts. Some can be synthesised, some must be obtained from diet. Vitamins are important because they are needed to make particular enzymes. |
|
|
Surface area : volume ratio |
Cells stay small because it is the most efficient way; more surface area to volume is desirable for exchange. Larger organisms adapt to have more surface area in organs to meet the exchange needs. |
|
|
|
Specialised cells |
Cells may be specialised for a particular function. Their structure will allow them to carry this function out. E.g. haemoglobin carries oxygen in red blood cells. |
|
|
|
What is diffusion? |
The net passive movement of substances (liquid, gas) from a region of high concentration to a region of low concentration (along a concentration gradient). |
|
|
|
Movement across plasma membranes depend on: |
- Temperature - Concentration gradient - Composition of membrane - Nature of substance being exchanged |
|
|
|
Lipid-soluble, non-polar (alcohol) DISSOLVE Very small molecules (water) PASS BETWEEN MOLECULES Small, uncharged molecules (O2) PASS DIRECTLY THROUGH Large, polar, water-soluble substances (amino acids, simple sugars) SPECIAL CHANNELS e.g. protein channel |
|
|
|
7 Factors affecting rate of diffusion: |
- Concentration gradient - Distance moved - effective over short distances - Surface Area - the more area the higher the rate of diffusion - Barrier thickness (thin is desirable) - Temperature (warmer = faster diffusion) |
|
|
|
Passive transport: |
-Diffusion - osmosis Facilitated diffusion - glucose transport |
|
|
|
Active transport: |
-Proteins and ATP - Na/K Pump -Endocytosis (phagocytosis and pinocytosis) -Exocytosis (secretion) |
|
|
|
Phagocytosis |
Cell eating. Whit blood cell engulfs debris. |
|
|
|
Pinocytosis |
Cell drinking |
|
|
What is Osmosis? |
Osmosis is the net movement of free water molecules across a semi permeable membrane. Concentration gradient is called the osmotic gradient .Pressure causing water to move along this gradient is the osmotic pressure. |
|
|
|
Endocytosis |
External particles near theplasma membranes are enclosed by the membrane and are 'pinched' off to form avesicle enclosing the particle. The vesicle then becomes fused with thelysosome so that its contents can be digested. |
|
|
|
Exocytosis |
is the movement of as substance OUT OF the cell FOR SECRETION via vesicles that connect with the plasma membrane and release contents. E.g. Neurotransmitters between neurons. |
|
|
|
Flow of cells --> systems |
CELLS --> TISSUES--> ORGANS --> SYSTEMS |
|
|
|
What is the environment of living cells? |
All cells exist in a watery environment The environment of living cells is this EXTRACELLULAR FLUID that is in contact with the plasma membrane Extracellular fluid is located outside cell membranes; includes blood plasma and interstitial fluid. |
|
|
|
Interstitial fluid |
Extracellelar fluid that is in the spaces between cells in tissues. |
|
|
|
What is the internal environment? What is regulated? |
Internal environment is independent to the external environment. Common aspects regulated include: -Concentrations of particular salts (ions) -Temperature -Concentrations of nutrients, water and wastes -Acidity or alkalinity (pH) |
|
|
|
The internal environment of a flowering plant |
No clear distinction between the external environment and the extracellular fluid of the internal environment. The cytosol of plant cells is usually more solute concentrated to draw in water by osmosis. Cells would burst if not for the rigid cellulose wall. Plants can withstand more fluctuation than animals. |
|
|
|
Organelle membranes |
Organelles have different chemical contents due to discrete compartments made within the cell by non-plasma membranes. |
|
|
|
Functions of membranes |
-Control type molecules enter and leave cells and cell components -Active environment where many essential chemical reactions occur -Compartments that separate organelles -Restrict movement of substances -Receptors involved with intracellular communication -Produce electrical activity in excitable cells |
|
|
Membrane composition |
Phospholipid - A molecule consisting of a long-chain fatty acids (hydrophobic) and a phosphate (hydrophilic); the major component of cell membranes. All membranes have a basic structure; two layers of phospholipid molecules associated with proteins, carbohydrates, cholesterol and more Most cells asymmetrical - different sides of membrane have different properties. (different pattern)]&card_back_html[]&card_hint_html[] |
|
|
|
Role of cholesterol in cell membrane? |
Cholesterol molecules provide stability ti the membrane without greatly affecting the fluidity, and reduces the permeability to small water molecules. |
|
|
|
Can proteins move in the cell membrane? |
Protein molecules are able to move to some extent but this may be limited to parts of the cell membrane. They provide channels through which water-soluble molecules and ions pass. |
|
|
|
Different membranes. |
|
|
|
What do membranes do? |
Membranes control the movement of substances within cells and between cells and their environment. |
|
|
|
What are tissues? |
Tissues are organised groups of similar cells. |
|
|
|
What connects plant cells? |
Plant cells connected by plasmodesmata and cytoplasmic strands. |
|
|
|
How are animal tissues held together? |
Animal tissues are held together in junctions between plasma membranes: -Tight junctions - limit extracellular fluid -Fibrousconnections hold cells together -Gap junctions - allow nutrients and ions to pass from the cytoplasm of onecell to another |
|
|
|
What specific chemicals allow long distance communication? |
Specific chemicals, hormones, allow long distance communication. They are secreted by endocrine glands or plant tissue. - Protein hormones - interact with receptors -Steroid hormones - pass through membranes and interact with receptors within the cell Nerves communicate chemically |
|
|
|
How does short distance communication occur between cells of the same tissue? |
Communication occurs between adjacent cells within the same tissue (cell-cell interactions) |
|
|
|
3 things Functioning cells complete: |
-Synthesise organic molecules -Transform energy -Break down unwanted substances |
|
|
|
The active site binds to the ___________? |
Substrate. |
|
|
|
In relation to forming or breaking apart molecules, what do enzymes do? |
Enzymes can BRING TOGETHER or BREAK APART two molecules. |
|
|
|
Are chemical reactions reversible? |
Most chemical reactions are reversible. The same enzyme can catalyse a reaction in either direction |
|
|
|
Are enzymes used up in reactions? What is necessary in the diet to make new enzymes? |
Enzymes are not used up in reactions, so cells can reuse them over and over again. When they eventually become WORN OUT, vitamins in the diet are needed to make new enzymes. |
|
|
|
What happens if there are excess reactants or accumulation of product in chemical reactions? |
In chemical reactions, if excess reactants - net reaction to the right. Accumulation of product - net reaction to the LEFT. |
|
|
|
Enzymes are specific. They (3): |
-Each enzyme catalyses only one type of reaction, specific to particular types of reactions (due to being a protein and having a three-dimensional structure) -Active sites and substrates structurally complementary -pH therefore affects activity of enzymes as is protein |
|
|
|
Enzymes are effected by temperature; TheyL |
- The faster molecules move, more often substrate will collide with active site. Too much heat damages Denaturation - irreversible change in protein structure. Freezing does not denature. -Most enzymes have an optimum temperature, usually just below critical temperature. |
|
|
|
Denature |
Irreversible change in protein structure. Freezing does not denature. |
|
|
|
Competitive inhibitors (enzymes) |
Molecules present that fit the enzyme's active site, and so slow the reaction. |
|
|
|
Enzymes are affected by other factors (2) |
-Amount of substrate or enzyme present -Whether there is accumulation of product |
|
|
|
Co-enzymes |
Very small molecules - less complex than proteins - associated with particular enzymes and are essential for their activity. |
|
|
|
Can enzymes be synthesised by animals? |
Most cannot be synthesised by animals, must be obtained from plants or microorganisms. |
|
|
|
All types of living cells (7): |
- Synthesise -Remove wastes -Obtain nutrients -Provide energy for movement and metabolism -Produce biological molecules for new organelles or repair use -Cells in multicellular organisms can specify function -All cells use chemical energy; it is stored in bonds of molecules |
|
|
|
Where is chemical energy stored? |
Chemicalenergy is stored in the bonds or connections that join atoms together. Releasedwhen broken apart. |
|
|
|
Complex to simple chemical reaction. |
Whenenergy is released it is CATABOLLIC reaction (complex to simple). |
|
|
|
Simple to complex chemical reaction. |
ANABOLLICreactions are when two substances are combined to make a more complex molecule- uses energy. |
|
|
|
All organisms need a source of _______ energy. |
Chemical |
|
|
|
Where do animals store glycogen? |
In muscles and in the liver. |
|
|
|
What is an immediate source of energy? |
ATP |
|
|
|
What is the ultimate source of energy? |
The Sun. |
|
|
|
Once and ATP (adenosine triphosphate) molecule has given up its energy it becomes: |
ADP (adenosine diphosphate). |
|
|
|
Can ADP be "recharged"? |
Yes, it uses less energy to restore ADP to ATP than to make a whole new ATP molecule. |
|
|
|
How do cells get their energy? |
Break apart glucose molecules to make ATP. |
|
|
|
What are the reactants of photosynthesis? |
carbon dioxide, water, sunlight |
|
|
|
What are the products of photosynthesis? |
Oxygen, water, glucose |
|
|
|
How many molecules of ATP are produced in aerobic respiration? |
36-38 molecules of ATP. |
|
|
|
What is cellular respiration? |
The complete breakdown of glucose to provide energy in cells. |
|
|
|
The initial stage of glucose breakdown is called: |
Glycolysis |
|
|
|
Glycolysis produces: |
2 pyruvate molecules and 2 ATP |
|
|
|
Glycolysis occurs in the __________ and is ___________. |
cytosol, anaerobic. |
|
|
|
Glycolysis produces 2 ATP molecules very rapidly. If oxygen is available, then: |
glucose is further broken down to make an additional 34-36 ATP molecules. |
|
|
|
Aerobic respiration occurs in the : |
Mitochondria. |
|
|
|
Why do enzymes lower their activation energy? |
To allow the organism to function as too much energy would be used otherwise. An input of energy is still required. |
|
|
|
Light dependent reactions requires _____and occurs ____ |
-Require Light -In the thylakoid membranes (where chlorophyll is found in chloroplast membranes) |
|
|
|
What happens in the Light Dependent reaction? |
- H2O is split -O2 is given out as a by-product -H+ ion is shifted into the stroma -ATP is formed from light energy and is shifted into the stroma -Light energy provides energy for adenosine to bond to phosphate |
|
|
|
What happens in the Light Independent reaction? |
-ATP fixes CO2 to H+ ion, forming glucose |
|
|
|
What is the cycle of glucose being made called? |
The Calvin Cycle. |
|
|
|
What is the Krebs Cycle? |
The 2 pyruvate molecules go to the mitochondria and the Krebs Cycle breaks them down into ATP. |
|
|
|
Anaerobic respiration or fermentation produces: |
-Lactic acid in animals -Ethanol in plants |
|
|
|
Hypertonic |
High solute outside of cell. |
|
|
|
Hypotonic |
Low solute outside of cell. |
|
|
|
Isotonic |
Equilibrium of solutes |
|
|
|
Four types of teeth: |
Incisors, molars, canines and premolars. |
|
|
|
Function of incisors: |
Snipping and cutting. |
|
|
|
Function of Molars: |
Grind and increase surface area. |
|
|
|
Function of canines: |
Ripping and tearing. |
|
|
|
Function of premolars: |
Chewing. |
|
|
|
Mouth |
- Beginning of the digestive system |
|
|
|
pH of mouth |
7 |
|
|
|
Enzyme in mouth: |
amylase, breaks down starch into maltose |
|
|
|
Tongue rolls food into a ______ before it is swallowed. |
Bollus. |
|
|
|
Oesophagus |
-Muscular tube -Peristalsis (muscular movement) moves food down. -Transports food and fluid -No absorption -two sphincters |
|
|
|
Function of the epiglottis: |
Flexible flap that closes over the trachea to ensure food enters the oesophagus not the trachea. |
|
|
|
Sphincter |
Muscular ring. Controls movement. |
|
|
|
Stomach pH |
1-3 acidic |
|
|
|
Stomach function |
-Food storage organ -Food made into chyme by mechanical and chemical processes -Glands of stomach wall secrete hydrochloric acid, pepsinogen and gastric lipases. |
|
|
|
What is the role of HCL in the stomach? |
To kill bacteria in food and make an ideal environment for pepsin activity. |
|
|
|
What protects the stomach lining? |
Mucus, from the digestive fluids. |
|
|
|
What is chyme? |
Semi-fluid mixture of partially digested food as the result of chemical digestion and mechanical churning in the stomach. |
|
|
|
pH of the small intestine |
7-9 |
|
|
|
Three main components of the small intestine? |
Duodenum, jejunum and ileum. |
|
|
|
Main function of small intestine |
Absorbs nutrients of 90% of all food we eat |
|
|
|
Duodenum function |
Chyme released in. Pancreatic enzymes and bile secreted. Bile neutralises acid from stomach. |
|
|
|
What does bile do? Where is it secreted from? |
Emulsifies fats. Secreted from cells lining the intestine. |
|
|
|
Jejunum function |
Main absorption occurs here. |
|
|
|
Ilium function |
Absorption of amino acids, simple sugars, vitamins and minerals by active transport. Fatty acids diffuse directly through cell wall or villi |
|
|
|
Cells can be divided into eukaryotic and prokaryotic cells. Do both contain ribosomes? |
Yes |
|
|
|
As a cell grows its volume _________ more than its surface area. |
Increases |
|
|
|
Enzymes are needed in what amounts? |
Small amounts. And can be used again at the end of the reaction. |
|
|
|
Substances can be hydrophilic or hydrophobic. Which allows polar and which allows non-polar? |
Hydrophilic - polar Hydrophobic - non-polar |
|
|
|
The shape of a red blood cell (bacon cave disc) allows the cell to: |
Absorb and release oxygen more rapidly. |
|
|
|
What happens to the heart during a heart attack? |
Less oxygen and energy reaches the heart muscles and consequentially heart cells die. |
|
|
|
How are insects limited in size? |
They are limited due to the rate of diffusion of oxygen. |
Spiracles and trachea. |
|
|
Bacteria and amoeba are both single-celled organisms that reproduce by splitting in two. It can be stated reproduction in bacteria is ____________ not involving ____________ whereas amoeba uses __________ that does involve __________. |
Binary fission Mitosis Binary fission Mitosis |
|
|
|
Bacteria and prokaryotes split by binary fission as they lack a ________ and so asexually reproduce. They do not use mitosis or meiosis. |
Nucleus |
|
|
|
What is binary fission? |
A kind of asexual reproduction that occurs in prokaryotes and some single celled eukaryotes. |
|
|
|
Cellular respiration equation |
C6H12O6 + 6H2O --> 6CO2 + 6H2O + ENERGY |
|
