Science Human Biology

How do body systems work together?

They move oxygen, nutrients, and move waste to keep the body working

Metabolism

All the chemical reactions in the body

Catabolism

Breaks big molecules into small ones

Anabolism

Builds big molecules from small ones

Enzymes

Proteins that speed up reactions

How do enzymes work?

They have a shape that fits the substrate (lock and key theory)

What are the enzyme labels?

Enzyme, substrate, complex, products

How does temp. affect enzymes?

Too hot = enzyme breaks (denatures)

To denature?

when a enzymes loses its structure making it unable to bind to its substrate and catalyse a reaction

How does ph affect enzymes?

wrong ph = enzyme doesn’t work as well

More enzyme = ?

Faster reaction (until full)

More substrate = ?

Faster at first, then levels off

What do enzymes do in digestion?

Break food into smaller, digestible pieces

Amylase

Breaks down carbs

Protease

Breaks down protein

Lipase

Breaks down fats

What waste does the liver remove from the body?

Urea

Urea

A naturally occurring compound and waste product in mammals

What do the lungs remove?

Carbon dioxide

What do the kidneys remove?

Urea in urine

What does the nervous system do?

Sends and receives messages in the body

What is CNS (central nervous system)?

Brain and spinal cord

What is PNS (Peripheral Nervous System)?

All the other nerves

What do neurons do?

Carry messages

Parts of a neuron?

Dendrite, cell body, axon

What are the 3 neuron types?

Sensory, Connector, and Motor

Sensory neurons

goes to the brain

Connector neurons

Goes inside brain and spine

Motor neurons

Goes to the muscles

How do neurons connect?

Signals jump across synapses using chemicals

Cerebrum

Thinking and memory in the brain

Cerebellum

Balance and movement

Medulla

Breathing and heart rate

Hypothalamus

Controls body temp and hunger

Pituitary gland

Sends out hormones

Reflex

A quick, automatic action

Reflex arc path?

Stimulus → Sensory → Connector → Motor → Response

Why are reflexes important?

They protect you from harm

What does the endocrine system do?

Make hormones

What do hormones control?

Growth, blood sugar, mood, puberty

How do hormones find target cells?

They fit special receptors

What does the hypothalamus do?

Controls the pituitary gland

What is Homeostasis?

Keeping body conditions stable for survival

What is negative feedback?

The body fixing a change by reversing it

What is positive feedback?

when the body increases the change

How does insulin control sugar?

High sugar → insulin → sugar moves into cells → levels go down

Endotherm organism

Controls its own body temp

Ectotherm organism

Body temp changes with surroundings

Are nerve signals fast or slow?

Fast

Are hormones signals fast or slow?

Slow

Do hormone effects last long?

Yes, long lasting

Do hormone effects last long?

Yes, long-lasting

What kind of signal do nerves use?

Electrical and chemical

What kind of signal do hormones use?

Chemical only

Are nerve messages targeted or wide-spread?

Targeted (specific muscles/glands)

Are hormone effects targeted or wide-spread?

Can affect many cells/organs