Topic 1 - Key Concepts in Biology Flashcards
Are animal cells eukaryotic or prokaryotic?
Eukaryotic
Give an example of a prokaryotic cell
Bacteria
What are eukaryotic cells?
Plant and animal cells, have a nucleus which contains their DNA, complex
Function of nucleus
to enclose and contain genetic material
What is the cytoplasm?
A gel-like substance where chemical reactions take place
What is the cell membrane?
Controls the molecules that can enter and leave the cells
What are mitochondria?
Where aerobic respiration takes place
How much is one order of magnitude?
10x
What do plant and animal cells have in common?
They both have a nucleus, mitochondria, ribosomes, cytoplasm, and a cell membrane
What do plant cells have that animal cells don’t?
Chloroplasts, cell wall, and a vacuole
What are chloroplasts?
They contain chlorophyll and also are sites of photosynthesis
What is a cell wall?
Made from cellulose, strengthens the cell
What is the vacuole?
its filled with fluid called cell sap and it helps give the plant its shape
What is differentiation?
When cells become specialised
What happens during fertilisation?
The genetic info of the ovum and sperm combine
What are the adaptations of a sperm cell?
Long tail - allows them to swim to ovum(streamlined), mitochondria - gives them energy to swim, enzymes - allows them to digest their way through the outer layer of the ovum
What is the job of a nerve cell?
To send electrical impulses around the body
What does an axon do?
Carries electrical impulses from one part of the body to another
What is an axon covered in and what does it do?
Myelin, insulates the axon and speeds up the transmission of nerve impulses
What do the ends of axons have?
Synapses
What are synapses?
Junctions which allow the impulse to pass from one nerve cell to another
What do dentrites do?
They increase the surface area so the other nerve cells can connect more easily
Why are muscle cells packed with mitochondria?
To provide them energy
What do muscle fibres do?
Can change the length if the muscle cell, when a muscle cell contracts these protein fibres shorten, decreasing the length of the cell
What do enzymes break down?
Big molecules - proteins, lipids, some carbohydrates
What do digestive enzymes break down?
The food we eat so it can be digested
What are carbohydrates?
Enzymes called carbohydrases convert to carbohydrates to simple sugars e.g amylase breaks down starch
What are proteins?
Proteases convert proteins to amino acids
What are lipids?
Lipases convert lipids into glycerol and fatty acids
How are carbohydrates synthesised?
By joining together simple sugars
How are proteins synthesised?
Joining amino acids
How are enzymes synthesised?
Catalyse the reactions needed to do this
What is the equation for rate of reaction?
1000/time
