Biology-Karteikarten | Quizlet

Characteristics of living organisms

Movement - the movement of limbs and molecules and an organism changing shape or position

Respiration - the taking in of nutrients and oxygen to release energy for metabolism

Sensitivity - detection changes in the stimuli and making appropriate responses

Growth - a permanent increase in size and the development of more complex structures

Reproduction -the process that makes more of the same kind of organism

Excretion - the removal of waste products of metabolism, toxic materials and substances in excess

Nutrition - the taking in of nutrients for energy, growth and development

How does yeast turn to alcohol

Yeast respires anaerobically to make alcohol

Glucose --> Ethanol + water

Alimentary canal labelled

Difference between growth and development

Growth is a permanent increase in size

Development is developing more complex structures

Cell organisation

cell, tissue, organ, organ system, organism

Plant cell

Cell wall

Cytoplasm

Mitochondria

Chloroplasts

Cell membrane

Nucleus

Large permanent vacuole

Animal cell

Cytoplasm

Mitochondria

Cell membrane

Nucleus

Large permanent vacuole

Cell wall

increases surface area of the cell and helps support it

Nucleus

Contains cells DNA

Cell membrane

Controls what enters and leaves the cell

Large permanent vacuole

Stores cell sap and helps support the cell

Chloroplasts

where photosynthesis occurs and chlorophyll is found

Cytoplasm

fluid inside the cell

Mitochondria

Where aerobic respiration takes place and where the cells biochemical reactions take place

Metabolism

the chemical reactions that take place in a cell or in an organism

Specialized cells

Sperm cell= has a tail to swim

Root hair cell= long and thin, to absorb water and minerals from the soil

Red blood cell= biconcave to maximize surface area to carry more oxygen

Palisade cell= many chloroplasts to help perform photosynthesis

How to calculate magnification of biological specimens (mm)

1mm is 1000macrometers

Diffusion

the net movement of particles traveling from an area of high concentration, to an area of low concentration

Why is diffusion important?

Cells can use diffusion as a way of getting important particles in and out of them. Diffusion is particularly useful as it does not use any energy. To get into a cell, particles must pass through a selectively permeable membrane. This is good for small molecules though- like oxygen and carbon dioxide. It is important for the uptake of oxygen into blood down a concentration gradient and for the movement of water and minerals into the roots of plants.

Factors that affect diffusion

Temperature - the higher the temperature, the more energy particles gain and spread out faster

Surface area - the smaller the surface area, the more concentrated it will be, and diffusion will take less time

Concentration gradient - the higher the concentration gradient, the faster diffusion will happen

Osmosis

the net movement of water molecules from a region of higher water potential (low solute concentration), to an area of lower water potential (high solute concentration), through a semi-permeable membrane with passive transport

Passive transport

The movement of molecules through a cell membrane without using energy

Semi permeable membrane

a membrane that has tiny holes in it, which allows only small molecules to pass through

High solute concentration

a concentration which has a lot of solute (e.g., salt) and has low water potential (so not much water molecules). The water molecules travel to a high solute concentration, to reach equilibrium on both sides of the semi permeable membrane, as a high solute concentration has a low water potential

The difference between osmosis and diffusion

Osmosis can only occur in liquids and through a semi permeable membrane, whereas diffusion occurs in all three states of matter

Balanced diet

having the right amount of each needed nutrient

Main nutrients (FFVVPICWC)

Fibre = supports digestive system (beans)

Fats= support cell function (nuts)

Vitamin C = supports immune system (fruit)

Vitamin D = helps absorb calcium (fish)

Protein = build and repair body tissues (eggs)

Iron = helps red blood cells carry oxygen (bread)

Calcium = vital for bones and teeth (dairy)

Water = prevents dehydration

Carbohydrates = source of energy (bread)

Effects of vitamin D deficiencies

Condition formed is Ostemelacia. This causes weak bones and muscles and pain

Effects of iron deficiencies

condition formed is anemia. This decreases production of red blood cells so not enough oxygen gets carried around the body

Effects of protein deficiencies

conditions formed are kwashiorkor and marasmus. They have tummy bloating, brittle hair, thin arms and legs, stunted growth

effects of fibre deficiencies

constipation

Biomolecules

organic molecules found in living things. They are substances produced by living organsims

Macromolecules/ organic molecules

Carbohydrates= Carbon, hydrogen, oxygen

Fats= Carbon, hydrogen, oxygen

Proteins= carbon, hydrogen, oxygen, nitrogen

types of teeth

incisors, canines, premolars, molars

Incisors

Front teeth, used for cutting

Canines

on either side of incisors, used for tearing

Pre-molars

teeth between canines and molars, used for grinding and chewing

Molars

back teeth used for crushing and grinding

Layers of the tooth

Enamel

Dentine

Pulp

How does tooth decay form

Bacteria feed on and respire on the sugars on your teeth, and produce decay as a toxic waste product. To avoid this, brush your teeth and not eat sugar

alimentary canal

the whole passage along which food passes through the body from mouth to anus.

Ingestion

Digestion

Absorption

Assimilation

Egestion

Ingestion

the taking in of food by mouth

Digestion

the chemical and mechanical breakdown of food inside your body

Mechanical digestion

Physical breakdown of large pieces of food into smaller pieces

Chemical digestion

Enzymes break down food into smaller molecules

Absorption

the villi and microvilli in the small intestine absorb the food molecules, and into the blood

Assimilation

the food molecules traveling through the blood and becoming part of cells

Egestion

the removal of unused food

Why does food have to be digested?

for breaking down food into nutrients which the body uses for energy, growth and cell repair

Two main features of the small intestine to enable maximum absorption

Villi and microvilli

Villi

Tiny hair-like projections that line the inside of the small intestine. They contain blood vessels and help absorb nutrients.

microvilli

fingerlike projections that line along the small intensines wall

Label villi

Internal membrane = increases surface area for food absorption

Capillary network = transports nutrients through the blood to cells

lacteal = absorbs dietary fats

Enzymes

Biological catalysts that speed up chemical reactions. They are made of amino acids (proteins). Amylase, lipase and protease (types of digestive enzymes) break down food

How does an enzyme break down food?

1) the substrate bonds with the active site (lock and key)

2) an Enzyme substrate complex is formed

3) the substrate reacts to form a product which then leaves the active site

4) the enzyme can be used again - it is regenerated (unless its denatured)

Factors affecting enzyme activity

Temperature= each enzyme has an optimum temperature, and as the temperature increases, the enzyme activity speeds up (as they gain energy). However when the temperature is above their optimum temp, they vibrate too much and denature

pH= each enzyme has an optimum pH, and as the acidity increases, so does the enzyme activity. However when the pH is above their optimum pH, they denature

Macronutrients (Polymers to monomers) and which enzymes break them down

lipids →(lipase) → glycerol + fatty acids

Proteins → (protease) → amino acids

Starch → (amylase) → glucose

Solutions used for testing Protein, glucose and starch

Protein= Biuret. Add drops of biuret solution to the food sample. The food sample will contain protein if it changes from blue to purple

Glucose= Benedicts solution. In a test tube, add benedicts solution to the 'solution to be tested' and heat up in a water bath. If reducing sugar is present in you 'solution to be tested', a colour change will occur from blue to orange

Starch= iodine. Add drops of iodine to the food sample. The food sample contains starch if it changes from orange-brown to blue-black

fats= ethanol. Add drops of ethanol and water to solution, and shake. Fat is present if a fatty layer, called cloudy emulsion forms

Catalyst

any substance that speed up a chemical reaction, without itself being consumed

Circulation

the movement of blood around the body through blood vessels

Circulatory system

made up of the heart, blood vessels, and blood. It supplies all your cells and organs with the substances they need (oxygen, glucose)

Heart anatomy

The heart has 4 chambers:

Right atrium

Right Ventricle

Left atrium

Left ventricle

Deoxygenated blood enters the right atrium, where it gets forced into the right ventricle (the valves prevent backward flow of blood) where it then leaves through the pulmonary artery

Oxygenated blood from the lungs enters the left atrium, where it gets forced into the left ventricle where it then leaves through the aorta

Double circulatory system

Blood passes through the heart twice in one complete circuit of the body e.g. in a human

The right side of the heart pumps deoxygenated blood from the body to the lungs where it collects oxygen. The oxygenated blood gets pumped back to the heart and then to the body where it supplies it with oxygen. The now deoxygenated blood travels back to the lungs. It is a double circulatory system because blood passes through the heart twice per circuit.

Valves

prevent back flow of blood

Arteries

carry blood away from the heart (aorta and pulmonary artery)

Veins

carry blood back to the heart (vena cava and pulmonary vein)

Capillaries

Smallest blood vessels, that connect veins and arteries, and transport nutrients (from the villi) to the cells

components of blood

Plasma

Red blood cells

White blood cells

Platelets

Plasma

They take nutrients, hormones and proteins to the needed body part. They carry water salts and enzymes

Red blood cells

Transports oxygen around the body, from the lungs to the body cells. They have lots of hemoglobin which carries oxygen.

They are small and flexible which allows them to fit through narrow vessels

They have a biconcave shape which maximizes their surface area to absorb more oxygen

White blood cell

They produce antibodies to fight diseases. They have an irregular shape, so they can change shape to go to the site of infection

Platelets

Make blood clot, so that you don't bleed much when cut and they stop illnesses entering the body. They can attach to other platelets to clump together to form a clot.

coronary arteries

They supply the heart muscle with the oxygen it needs for respiration

coronary heart disease

An artery disease caused by plaque buildup in the wall of the arteries that supple blood to the heart. Plaque buildup causes the inside of the arteries to narrow over time and cuts off the supple of blood and oxygen to the heart muscle.

When the coronary arteries narrow, the heart needs to pump faster to force more blood through

Risk factors of coronary heart disease

-smoking

-physical inactivity

-alcohol

-obesity

-salty food

-genetic factors

-unhealthy food

-stress

respiratory system

the lungs, air passages, and breathing muscles; supplies oxygen to the body and removes carbon dioxide

Gas exchange

The diffusion of gases from a region of higher concentration to a region of lower concentration. It is Oxygen moving from the lungs to the bloodstream. That is why there is less oxygen when you exhale air, than when you inhale air, as our cells use oxygen to release energy, and give out carbon dioxide as a byproduct

How an oxygen molecule, moves from the air into our cells

When we breathe In, the oxygen molecules travel down the trachea and into the bronchi. Then it moves from the bronchi into the bronchioles and into the alveoli. The oxygen molecules then diffuse from the alveoli into the capillary where the blood flows, and into the red blood cell.

Cilia

small, hair like structures on all mammalian cells which help move mucus up and out of the lungs

goblet cells

They produce mucus and create a protective mucus layer

mucus

It is a slippery goo produced by the goblet cells

Cilia, goblet cells and mucus: what do they do

Mucus, which is produced by goblet cells, traps particles such as bacteria and dust. This prevents dust from entering the lungs. Cilia waft in a wave like motion in order to move mucus away. Cilia move mucus to the throat

Trachea are cleaned by cilia which sweep fluids and foreign particles out of the airway to keep them out of the lungs

Inhalation

Diaphragm contracts downward, ribs push out, lungs fill with air

Exhalation

Diaphragm relaxes upward, ribs relax, air pushes out

How do alveoli provide an efficient surface for gas exchange?

1) thin walls (one cell thick)

2) Moist for rapid diffusion

3) They are surrounded by lots of blood vessels (capillaries) to carry oxygen away and maintain the gradient

4) they have a very large surface area

Why is smoking bad?

-smoking damages the cilia and therefore the cilia cannot sweep mucus to the throat to swallow. Smokers have to cough up mucus

-Nicotine speeds up the heart rate and blood pressure which damages blood vessels or could lead to a heart attack

-Burning tobacco releases carbon monoxide which is poisonous as it attaches to haemoglobin in red blood cells

alveoli

air sacs in the lungs

bronchi

The passages that direct air into the lungs

bronchioles

smallest branches of the bronchi. If they fill with fluid, the alveoli can swell up and explode

trachea

Allows air to pass to and from lungs. The windpipe

Asmtha

bronchioles fill with mucus, and muscles fail to dilate properly

Passive smoking

Inhaling second-hand smoke

Aerobic respiration

Respiration that requires oxygen. It occurs in the mitochondria and produces energy from glucose and oxygen

Aerobic respiration equation

glucose + oxygen → carbon dioxide + water (+energy)

Anaerobic respiration

Respiration that does not require oxygen and releases less energy, but more quickly than aerobic respiration. It happens when there is not enough oxygen delivery to the muscle (oxygen debt)

Anaerobic respiration equation

glucose → lactic acid + water (+ energy)

Respiration

the transfer of oxygen from the outside environment to cells within tissues, as well as the removal of carbon dioxide. This happens in the mitochondria. There are two ways of respiration: aerobic and anaerobic

Why is there more oxygen when you inhale than exhale air?

There is less oxygen when you exhale air, than when you inhale air because our cells use oxygen for energy and produce carbon dioxide as a byproduct. So there is more carbon dioxide and less oxygen in exhaled air. Cells taking in oxygen and giving out carbon dioxide for energy is called respiration.

Cellular respiration

the process by which cells use oxygen to produce energy from food

Oxygen debt

a lack of oxygen that develops in the body during periods of intense activity. It is an oxygen shortage in the body tissues. When our bodies have an oxygen dept, that is when anaerobic respiration takes place