Biology locked in

Cardiac muscle

never fatigues, each muscle cell has connections with other muscle cells which allows waves of electrical excitation to pass evenly across the heart muscle tissue

Coronary arteries

delivery oxygen and nutrients to the cardiac muscle

Cardiac veins

remove the cellular waste

How does a coronary heart disease occur

The coronary vessels can begin to become narrowed due to build up of fatty deposits in the wall of the blood vessel. These fats are present in the blood and begin to build up after some sort of damage to the inner lining of the blood vessel

How does a heart attack happen

When the muscle cannot receive oxygen and glucose to perform aerobic respiration therefore cannot contract

Factors that cause coronary heart disease

smoking, high blood pressure, stress, no exercise

Arteries

carry oxygenated blood at high pressure away from the heart

Veins

carry deoxygenated blood at low pressure towards the heart

Plasma

carry blood cell around the body and dissolved nutrients. Allowed heat energy to be carried. Allows hormones to move around the body

How are blood cells adapted for their role

no nucleus gives it more space for haemoglobin, small size allows them to squeeze through the arteries, buncave shape to increase surface area for oxygen absorption

Platelets

allow the blood to clot

Iron

used to make haemoglobin

Main components that are carried by plasma

red blood cells, white blood cells, platelets

Capillaries

carry blood through organs

Substances that diffuse through capillary walls

oxygen and nutrients

Arteries structure

Elastic, thick wall to allow dilating and constricting

Veins structure

Less elastic, less thick as low pressure

Semilunar valves

prevents backflow of blood in veins

Capillaries structure

small, one cell thick walls

Pulmonary vein

carries oxygenated blood from the lungs

Pulmonary artery

carries deoxygenated blood from the heart to the lungs

Hepatic vein/ artery

blood to the liver

Renal artery /vein

blood to the kidneys

Hepatic portal vein

blood from digestive system to liver

Breathing in

muscles contract lifting the ribcage upwards and outwards, the diaphragm contract pulling down, volume increases pressure decreases

Breathing out

muscles relax, ribcage goes downwards and inwards, diaphragm moves upwards, volume decreases pressure increases

Adaptations of alveoli

large surface area, thin walls, rich blood supply

Journey of air through the lungs

Trachea, Bronchi, Bronchioli, alveoli

Enzymes

are proteins that increase the rate of chemical reactions by lowering their activation energy

activation energy

is the energy required in order for a given reaction to start

Catalysts

work by speeding up chemical reactions without being used up

What are carbohydrates broken down into

starch to sugar

what are proteases broken down into

protein to amino acids

what are lipases broken down into

fats into glycerol

What increases frequency of collision

temperature, concentration of enzyme and substrate

active site

the part on the enzymes where the substrate locks, it is a special shape

What is the effect of high temperature on enzymes

the enzyme will denature

what converts starch into maltose

amylase

4 stages of digestion

ingestion, digestion, absorption, egestion

types of digestion

mechanical and chemical

mechanical

physical breakdown of food

chemical

breakdown of food by action of enzymes

saliva

contains amylase to break down starch

Stomach

contain hydrochloric acid, digests carbohydrates and proteins

liver

makes bile

bile

substance that neutralises acid and breaks down lipids into smaller droplets to make larger surface area

pancrease

releases enzymes into small intestine

amylase

converts starch into maltose

maltase

converts maltose into glucose

small intestine

absorbs nutrients, digests carbohydrates, proteins and lipids

small intestine adaptations

lots of villi which increase surface area for absorption, wall of villi is one cell thick to minimise diffusion distance, excellent blood supply to get nutrients into the blood

large intestine

does the remaining absorption of water to leave bulk of waste

peristalsis

is the contraction of muscles along the digestive system to squeeze food along

carbohydrates

can be simple sugars or complex starch

proteins

needed for growth, made of single units amino acids

lipids

store energy, are made up of glycerol and fatty acids

Fibre

not digested, used to help move food throughout the intestines

Carbohydrates (chemical composition)

carbon, hydrogen, oxygen

monosaccharides

glucose, fructose, galactose

disaccharide (maltose)

glucose and glucose

disaccharide (sucrose)

glucose and fructose

disaccharide( lactose)

glucose and galactose

polysaccharides

starch, glycogen

Protein (chemical composition)

carbon, hydrogen, oxygen, nitrogen

Lipids (chemical composition)

carbon, hydrogen, oxygen

Forms of lipids

fats and oil

Lipids structure

glycerol with fatty acids chains

Test for starch

add iodine, dark brown→purple if positive

Test for protein

add Biurets, light blue→light purple if positive

Test for glucose

add benedict’s and heat in hot water for 2 mins, blue→ orange if positive

Test for lipids

add Ethanol and shake, add equal amount of water, clear→ cloudy if positive

Diffusion

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

factors affection diffusion

distance, surface area to volume ratio, temperature, particle size

Osmosis

is the net movement of water across a partially permaeble membrane from a place of high concentration to low concentration

Factors affecting osmosis

surface area to volume ratio, temperature, difference in water potential

active transport

is the movement of dissolved molecules into or out of cell through the cell membrane from a region of lower concentration to high concentration using Atp energy

factors affecting active transport

temperature, surface area to volume ratio, energy availability

why does bacteria not need a circulatory system

bacteria has large surface area to volume ratio and can survive of diffusion

why does mammals needs circulatory system

mammals have small surface area to volume ration and diffusion will take to long

two types of circulatory system

sing circulatory system(fish), double circulatory system(mammals)

Features of double circulatory system

pulmonary and systemic circulation

pulmonary circulation

carries deoxygenated blood from heart to the lungs and vice versa

systemic circulation

carries oxygenated blood from heart to the cells and vice versa

Why is the double circulatory system more efficient

maintains pressure, blood travels quicker to organs, faster delivery of nutrients, supports high metabolic demands

What is the main purpose of a circulatory system

is the facilitate the flow of material over a distance

Chambers of the heart

pump blood at different pressure and speeds

which parts carry oxygenated blood

left atrium, left ventricle

which parts carry deoxygenated blood

right atrium, right ventricle

which parts carry oxygenated blood

left atrium, left ventricle

cetroventicular valves

tricuspid valve, bicuspid valve

what are valves for

ensure that blood flows in one direction

atria

are the upper chambers of the heart, are thin walled and elastic

ventricles

are the lower chambers of the heart, they have thicker walls to pump blood

Levels of organisation

organelle, cell, tissue, organ, organ system

Organelles

membrane bound structure within the cell with specific functions

tissue

group of cells working together to perform a function

organ

several tissues carrying out a specific function

organ system

a group of organs

eukaryotic cells

contain membrane bound organelles